2020 : The second set is much closer but it's Knowles and Groenefeld who reach the final after clinching it 7-5 - capping off a bad day for the Murrays. The will now meet top seeds Leander Paes and Cara Black for the mixed doubles title on Sunday.

1935 : The atmosphere is rather subdued following the disappointment of Andy's defeat and matters have now got worse for the Murray family with Knowles and Groenefeld taking the opening set 6-2 in this mixed doubles semi.

1910 : It may well be all over for Andy Murray at this year's Wimbledon but his brother Jamie is currently in mixed doubles semi-final action with his partner Liezel Huber against Mark Knowles and Anna-Lena Groenefeld.

1844 : But it's all over now as Murray drills a backhand into the net during an unbelievably nervy rally and Roddick sinks to his knees as he celebrates an emotional victory! What an incredible match that was and the American will now contest his third Wimbledon final against Roger Federer.

1842 : A backhand down the line from Murray is correctly - but agonisingly - called out after a Hawkeye appeal. But then at match point down Murray then passes Roddick with a breathtaking winner to stay in the championship!

1842 : Murray simply has to win these next two service points and sticks to the old formula on the first of these when waiting for Roddick to make a mistake - which he duly does. On the second Murray, sticking to the same gameplan, pulls out a stunning cross-court winner to stay alive - now it's down to Roddick to close out the match...

1838 : Murray holds his nerve in a long, tense rally on the next point and waits for Roddick to eventually send a shot into the net. The American is back on serve now with a 3-2 lead and this quickly becomes 5-2 when Murray fails to return on two successive occasions.

1837 : The opening three points go with serve but then Roddick edges 3-1 ahead when Murray sends a lazy forehand from the baseline into the net. Could that prove pivotal in this tie-break?

1835 : Help from the net cord allows Murray to level this game up at 15-15 when a wrong-footed Roddick then pushes a volley into the net. But the American responds with an ace to get his nose in front again. The crowd then will Murray to reach a drop shot but when he gets there he can only send it into the net, giving Roddick a 40-15 lead and shortly after the game is sealed. Now we have another tie-break! Can you cope with this drama?!

1831 : Murray looks a cool customer once again as he sends down a flurry of powerful first serves to move 40-0 up. A wonderful Roddick winner down the line pulls one back before a Murray error makes the home crowd sweat - surely he can't crumble now. The Scot displays his guts and determination to unleash another strong first serve which Roddick can't get back over the net and that's now a lead of 6-5 in the fourth set.

1828 : One of Roddick's most prolific shot in rallies has been the volleyed forehand at the net and once again it works a treat as he moves 15-0 up. Murray then sends an attempted backhand down the line wide before two unreturnable first serves finishes off the game.

1825 : Some supporters are having difficulty watching this through their fingers but they'll be calmed by Murray's ruthless performance in this game, only dropping a single point as well as drilling home some morale-boosting winners. Now Roddick must serve to stay in this fourth set.

1823 : Murray has a great chance when Roddick's first serve is out but in the ensuing rally, the American holds his nerve to fire a forehand winner to level it up at deuce. He then draws Murray out wide in the next point before having all the court to aim at for another winner before an overhead smash wins him the game.

1821 : Roddick's speed of serve is beginning to slow, giving Murray more opportunity than ever in this match to steal a break. He forces to critical mistakes from the American to earn a break point at 30-40...

1818 : Murray holds to love to edge ahead 4-3 but it's impossible to tell which way this game is heading. I personally feel the 22-year-old Scot will force a decider and from there the momentum of the waves should see him sail into the final.

1815 : It's another hard-fought service game for Roddick, who despite leading 40-15 is pulled back to deuce after a superb Murray winner and an error having struggled to cope with the spin on the ball. Roddick then pounces at the net, showing great reflexes to find the winning angle and volley past a scampering Murray. The game is sealed on the next point and it's now 3-3 in this fourth set.

1809 : This crowd really needs to find its voice again to lift Murray, who looks extremely downbeat right now. At 15-40 the British hope makes two silly errors - born out of frustration - to be drawn back to deuce and Roddick must really fancy his chances now. A strong first-serve from Murray gives him advantage and after a long rally he eventually prevails when a Roddick backhand crashes into the net.

1805 : Murray wins the first point on Roddick's next service game but the American remains strong and claws his way back for a relatively comfortable hold.

1804 : Darren Brown from Newcastle has emailed in to say: "Am glued to my computer watching this, its nail biting stuff between Roddick and Murray. Roddick pulls in front but Murray serves up and catches back up after winning three games in a row earlier. COME ON MURRAY!"

1802 : At 30-15 Roddick has a great opportunity to put away a volley at the net but instead gets embroiled in doubles-esque rally which Murray comes out on top. It gives Murray the breathing space to clinch the game and he keeps his nose in front at 2-1 in this fourth set.

1759 : Roddick takes advantage of the subdued atmosphere, dropping just a solitary point on his way to an easy service hold. You wonder if the American will go for broke in order to finish this match quickly or play a waiting game for Murray to make mistakes under increasing pressure.

1757 : The crowd go quiet as Murray double-faults, perhaps highlighting just how the momentum has swung in the favour of Roddick. However the British star gets back on track to hold serve in the opening game of this fourth set - although you can hear a pin drop now on Centre Court.

1755 : This is where the mental side of tennis comes to the fore and it's up to Murray now to keep calm and re-discover his 'A' game. By contrast Roddick is now in that position where so many players choke so it's crucial that he too maintains his composure in these tense moments on court.

1752 : Nerves are really jangling right now and it's Murray who suffers under the pressure when putting a routine forehand into the net. Roddick celebrates - as do his supporters in the box - as he takes the third set in this gripping semi-final showdown.

1751 : Murray saves it with a crisp winner much to the relief of the crowd but then an error on the next point gives Roddick the chance to serve for the set...

1750 : Every spectator is on the edge of their seat throughout the next rally as they await Murray to clinch the set, but instead it's Roddick who dinks a lovely drop shot over the net to make it 6-6. An awesome ace follows and he now has a set point...

1748 : There is so much tension inside the Centre Court arena and now it's Roddick's turn to feel the pressure as he falters on serve to allow Murray to break back. Meanwhile the British number one slams down his third ace in a row to move 6-5 up and earn himself a set point - on Roddick's serve...

1745 : A breathtaking cross-court forehand flashes past a beaten Roddick to restore parity but the crowd can only groan with dismay as Murray unbelievably hits the net when it seemed so much easier to strike the ball past a stranded opponent. And it gets worse for the Scot when Roddick snatches another mini-break on the next point to move 4-2 up.

1744 : The crowd can hardly contain their excitement - and why would they want to - as Murray survives falling a mini-break down with a lovely passing winner down the line. But Roddick does indeed snatch first blood on the every next point when Murray hits wide to fall 1-2 behind.

1741 : Back to the action now and Murray is finding this game a struggle as he looks to force a third-set tie break. At 40-15 he double faults but then he responds with an ace to take the game. This really is a nail-biter now as we head into a tie-break...

1740 : Alison Hutcheson is convinced Murray will reach the final but Joseph Nthini reckons Roddick will prevail. Louise Josey adds: "I'm sorry to say that I think Roddick will do it but it will be a brilliant and nail biting match from start to finish."

1737 : Roddick could be forgiven for falling away in this third set having seen his great opportunity disappear but he comes through a tough service game to hold and put the pressure back on Murray.

1736 : Garvan Clearly is glued to his computor and says: "All I hope is that it goes to a thrilling five-setter and I will get to see Murray getting whipped. Come on 'the Rod'!"

1734 : Steve Ricketts has emailed in to say: "We should get behind Murray, he has made silly comments but could go on to be a British legend. David Beckham also made errors in his youth but he grew up, as Murray will when he realises that he needs the English behind him. Come on Murray!"

1733 : The crowd are chanting Murray's name over and over again at the start of this next game, and he manages to keep the momentum going with an ace. Every point Murray wins he lets out a roar of pumped up emotion and races into a 40-15 lead. Maybe he lacks composure when driving a forehand wide, but he makes amends with a powerful ace to level it up at 5-5.

1730 : Roddick saves the first break point with a cute volley at the net but he loses his cool in the next rally when hitting long, promoting Murray's mum to stand up and cheer!

1728 : Murray is clearly pumped up after winning the opening point in this crucial game and Roddick is seemingly buckling in this pressurised situation when hitting the net to fall 0-30 down. Roddick's spectacular diving effort to reach Murray's awesome cross-court backhand fails and now the Scot has three break points...

1727 : Murray is serving to stay in this set at 2-5 down and Roddick is making his life difficult with a couple of powerful winners to force deuce. Prior to that the American returned a serve which was clearly out and then went on to lose the point - then he wanted a Hawkeye appeal but his request was obviously denied. Murray then takes the next two points to win the game but now it's up to Roddick to serve for the set.

1724 : Meanwhile Catherine Rumbelow, who admits she's frustrated not to be able to see a tele (but does at least say she's enjoying the text commentary!), says: "I thinks Murray will pull out all the stops and rise with the crowd!"

1723 : Sushen Belbase from Kathmandu in Nepal says: "I think Roddick might just edge Murray out today. It's my gut feeling and I am trusting it. No other reasons really why I think Roddick will win - both are top players and equally good."

1722 : Roddick is keeping his nerves in check and more sold serving allows him to move 40-15 up. Murray then battles hard in the next rally and gives himself hope with an unstoppable cross-court backhand winner. The Scot then steps up a further feat with a backhand winner down the line and suddenly Roddick is faces difficulty on his serve. He responds the way he knows best with an ace but we're then back to deuce when a long rally goes the way of Murray. It's nervy stuff here on Centre Court but Roddick manages to pick up the next two points with a decisive volley at the net and then another ace.

1718 : An angry Murray channels his energy in the right way with a comfortable service hold to love but is now in desperate need of a break.

1716 : A few emails have come in over the past few moments. Paul Butterfillsays: "Roddick will win, Murray will crash and burn like all the previous failed British players before him. And we have even started with the crowd cheering every shot like its his last yet. Especially after what he said about the ashes, come on Roddick!" Meanwhile Stuart Rankin adds: "Well its' anybodys game at the minute but I think Andy Murray can take the game to Roddick. Looks like we could be in for another classic 5 setter though."

1714 : It's an easy hold for Roddick, who moves into a 4-1 lead but the drama unfolding right now is a battle between Murray and the umpire! The British number one is fuming that he was called for apparent swearing and insists all he said was "Come on, pass!"

1713 : This time Roddick converts when a tired shot from Murray floats beyond the baseline and now the American leads 3-1.

1711 : The Scot saves this one with an ace even after Roddick's Hawkeye appeal. However Roddick quickly puts this disappointment behind him with an absolutely brilliant drop shot from the baseline to bring up another break point...

1709 : Murray saves the first with a beautifully floated lob shot over a stranded Roddick and another winner forces deuce. The Scot then fires down an ace but Roddick stays in the next point well before getting his reward when Murray lofts one long. Roddick digs in once again during the next rally and when Murray hits the net, the American has another break point. Surely he must take this one...

1706 : Brilliant from Roddick - at 15-15 he jumps into a Murray second serve to send a backhand winner past the British number one, who then hits wide to gift his opponent two break points...

1703 : So, with the set score level, who do you think will book their place in the final against Roger Federer? Let me know by emailing christopher.hammer@bskyb.com

1702 : The pressure is on Roddick as he falls 15-30 down but he gets back to basics with three successive first serves in which enable him to take the game and move 2-1 up in games.

1658 : That game has given Roddick a much-needed boost and follows it up by forcing Murray into a couple of mistakes to make the score in the next 30-30. And then after a long, absorbing rally the American is unfortunate to see his difficult attempt at a drop shot from the baseline just catch the net, giving Murray an opportunity to open up his account in the this third set - a chance the Scot takes with both hands.

1655 : A stretching Roddick then remarkably saves the third break point when his well directed drop volley at the net bounces twice just in the nick of time before the scampering Murray arrives. The American then polishes off the game with two clinical winners and how important a hold could that one be?

1653 : It's all going Murray's way right now and quickly moves 0-40 up on the Roddick serve - with more than a little help from the net cord I might just add on the second point. Murray then finds the net having been pushed wide by Roddick, who then cuts the deficit to just one point with a smash at the net. One to go...

1648 : And it's there - Murray wins the set after Roddick fails to return a powerful first serve. You'd have to say the British number one has the momentum heading into the third set while Roddick must now try and find away to unsettle his opponent just like he did in the first.

1647 : Murray wins the opening point with a clinical double-handed backhand winner at the net, and reproduces the same shot to move 30-0 up but this time from the baseline. An audacious attempt to lob Roddick just drifts out of play to give the American hope but it's soon 40-15 and Murray has two set points...

1644 : Roddick regains his composure for an easy hold to love, but now the focus turns to Murray, who will now serve at 5-4up for the second set. You can cut the tension on Centre Court with a knife...

1642 : As Murray edges closer to taking the second set, signs of anxiety are beginning to creep in looks. At 40-15 up he double faults before another needless error into the net sees the game move to deuce. Murray then lets out a scream of emotion when Roddick hits a backhand wide of the tramlines but it's nothing compared to the noise he lets out moments later when he clinches the game.

1636 : Roddick now holds to love but you just sense that Murray, who already has a break in this second set, is quite happy to wait for his own service games to come along.

1635 : The Centre Court crowd are really behind Murray, who is in full flow right now as he storms through another service game with three aces and a delicate pushed drop-shot winner.

1631 : Murray is the superior player right now and pulls off another forehand winner to beat an advancing Roddick at the net. The sixth seed battles back with some clinical first serves which allow him to take the next four points in succession and of course the game.

1628 : A confident Murray holds serve to love and Roddick really can't afford to let this set drift away so quickly.

1626 : Murray is really motoring now, reading the Roddick game in style to bring him into the net before passing him with a ruthless winner. The American responds by taking the next two points - the second of which resulting from a clinical volley at the net - and although an error brings the score to 30-30, Murray is unable to get his next two serves back and the game is won.

1622 : This match is really beginning to see some cracking tennis from both players. While Roddick claims the opening point with an unreturnable forehand down the line, Murray levels it up with a superb winner of his own. The British number one then slams down three aces on the bounce to move into a 2-0 lead in games.

1620 : Murray returns well again and when Roddick can only find the net the break is secured! What a comeback from the Scot while Roddick's earlier joy could prove to be short-lived.

1618 : Murray is visibly pumped up in this second set, letting out a scream when a stunning forehand from the baseline flashes past Roddick. He follows this up with two more sensational winners to earn himself three break points on the Roddick serve...

1616 : I have to say the way he broke Murray was completely out of character - but deserves plenty of praise for it. He produced plenty of variation throughout lengthily rallies and either carved out a winner or patiently waited for a mistake.

1614 : Once again Roddick holds his nerve during another well crafted rally, which ends when Murray sends a forehand into the net, giving his opponent the opening set.

1612 : Murray produces a little bit of magic to move 15-0 up with a flicked cross-court winner from the baseline to beat Roddick, who was lurking at the net. The next two points are shared before Roddick restores parity when forcing Murray into hitting wide after a very long rally. The American then hangs in another draining rally before finishing it off with a sublime drop shot to bring up break point...

1608 : Roddick's first-serve percentage is around the 85% mark at the moment and that's why Murray hasn't come close to a break yet. The sixth-seed holds to love and if he breaks Murray now he'll take the opening set.

1606 : One clear pattern of play which has become evident is that any rally lasting around more than 10 shots seems to always go the way of Murray. Unless the American wins a point early - he'll struggle to find a way past his opponent. The British number one sneaks into a 40-30 lead before a lovely double-handed backhand winner sails past Roddick and the game issecured.

1603 : Henman Hill (I don't bow down the pressure of calling it Murray Mound or Murray Mount!) is packed full of Murray fans and I'm sure it will explode with noise if he's able to book his place in the Wimbledon final later on.

1602 : Despite the help of a Hawkeye decision, Murray continues to struggle with the Roddick serve and falls 40-15 behind. The Scot then clings on during a long rally to beat his opponent with a lovely down-the-line winner but it's ultimately to no avail as he hits the net in the next point to give Roddick the game.

1600 : Vik Dowlul has emailed in once again to say: "This will be a comfortable routine victory for Murray. Roddick is far too one dimensional, granted he has the fastest serve in the game but he is up against he the best return of serve player in the world. Murray would have been tested more by the likes of Hewitt. Murray has always found it more difficult when against players who can mix it up a bit. This will be short and clinical. Straights sets and the dream final awaits!"

1557 : Murray controls this game well initially as he moves 40-15 up as he dictates the rallies and makes Roddick do all the running. A stunning back-hand return gives the American a sniff of hope but Murray then responds in the next point with a sublime volley at the net to move the score on to 3-3.

1554 : Heading into this match Murray won the last three encounters between the two and holds a 6-2 head-to-head record. They've only actually met once on grass - here in 2006 when Murray prevailed 7-6(4), 6-4, 6-4 in the third round.

1552 : Roddick is eager to keep the points as short as possible and goes for the kill early on his service points. After dropping the opening point, he swiftly recovers to win the next four on the bounce to edge 3-2 ahead in this opening set.

1548 : Murray is more settled throughout the longer rallies as it's Roddick who continually commits the errors. This game is as good as gifted to the Scot when the sixth seed balloons a forehand way too long at 40-15.

1544 : It's quite a tentative start from both men and give each other opportunities with a few careless unforced errors. At 40-15, Murray gives himself hope when a fine forehand down the line forces Roddick into a volley into the net but the American then powers down an ace to move 2-1 up in games.

1542 : Murray shows signs of a few early nerves on this massive day in his career as a couple of mistakes allows Roddick to force deuce. The Scot then hammers down an ace of his own to edge ahead before finishing it off with another!

1537 : Roddick is serving first and eases his way to a comfortable hold despite Murray's scurrying tactics. Two booming aces also sets the tone for what could be a tough afternoon for the British number one.

1530 : Andy Roddick by contrast has sweat buckets in reaching this stage of the competition having only once won in straight sets - his fourth round encounter against Tomas Berdych. Prior to that he needed four sets to dispose of Jeremy Chardy, Igor Kunitsyn and Jurgen Melzer while he was of course pushed all the way by Lleyton Hewitt in an epic quarter-final. Roddick has of course reached two Wimbledon finals - in 2004 and 2005 - but has yet to win it.

1528 : Andy Murray and Andy Roddick are due out on court very shortly - but before they do let's look at how they got here. Murray made hard work of Robert Kendrick in his opener before eventually winning in four sets but found life much easier against Ernests Gulbis and Viktor Troicki. Next was of course that epic 'night match' against Stanislas Wawrinka under the Centre Court roof as he kept the nation on the edge of their seats before edging though in five thrilling sets. The British number one produced more of hisbest tennis to comfortably oust Juan Carlos Ferrero and he now stands here with a great chance of becoming the first home finalist since Bunny Austin in 1938.

1525 : Susan and Ruth have amused me with their email, although they don't seem impressed with my typing speed! They say: "We are going to get the sack due to too much internet use at work! You say you can't keep up with the typing, so if we do get the sack can we have a job - we can type really quickly!"

1515 : Now attention turns to who Federer will face in his seventh consecutive Wimbledon final - will it be Britain's Andy Murray or America's Andy Roddick? Stay tuned to follow the drama right here with us!

1512 : Federer quickly moves 40-0 up before completing his straight-sets triumph with a thumping jumping smash at the net. It was a thoroughly clinical display from the five-time Wimbledon champion and Haas just didn't really have a chance. The final score 7-6 7-5 6-3 in two hours and two minutes.

1511 : Finally Federer takes his chance when Haas' sliced approach shot finds the net and now victory is surely his. He leads 5-3 in this third set and will now serve for the match.

1509 : Although break point is saved again after a fierce first serve, Federer fights hard in the next to force Haas into another error. Once again a well-placed first serve is too tough for Federer to return but a double fault then gifts him a fifth break point...

1508 : Courageously Haas saves them both before clinching one of the best rallies of the match with a Hawkeye-contested winner which clipped the baseline. A Haas error brings up deuce before Federer wins a draining baseline rally after a Hawkeye decision worked in his favour - but only just...

1504 : Haas is trying to cling on for dear life but when a rampant Federer sees the finish line there's nothing anyone can do. A pounding forehand winner puts the Swiss 15-30 up and then an unfortunate net cord means Haas now has two break points to defend...

1500 : Haas screams with frustration as he again fails to contend on the Federer serve, which is almost unreturnable. Another ace completes a love game and there's no way he'll be broken today.

1458 : The blue skies are breaking through over Centre Court with the crowd now basking in the sun. Federer and Haas do at least have the respite of a nice breeze but in terms of the match nothing really is changing as Haas comfortably holds to stay level in this third set.

1455 : Federer affords himself a smile after he lobs a shot wide after a stranded Haas puts his arms up at the net in a comedy way to distract him! It matters little as the Swiss hammers down an ace to move 3-2 up.

1452 : Is Haas chasing a lost cause right now? To his credit he remains strong on serve and doesn't want to fade out of this competition with a whimper. Having been on the back foot for most of the rally while level at 30-30, he forces Federer into a mistake then manages to take the game. Good fighting tennis from Haas in what are difficult circumstances for him now.

1447 : I just can't keep up with the typing when Federer is on serve! Awesome hitting power sees his race 40-0 up and he then finishes it off with an ace. You get the feeling Haas gives up on Federer's serve once he falls two points behind but you can't really blame him.

1446 : Haas responds in emphatic fashion, with an equally comfortable hold - although it's on his opponent's serve where he really needs to make an impression.

1445 : While I was reading that last email, Federer raced through his opening service game in this third set to love. It really was a case of blink and you missed it - which I did!

1444 : Mark Zurek thinks Federer is as good as through and is already looking ahead to the final. He says: "Ithink in Federer's form, if Murray can beat Roddick the final will go one of two ways. It will be a Wimbledon epic or Federer will win in straight sets.and be too strong for a tired Murray." Keep your emails coming in to christopher.hammer@bskyb.com

1442 : Let's not completely write off Haas - don't forget he took Federer to five sets in the fourth round of the French Open earlier this year, even though he did ultimately lose.

1440 : Haas responds with a thumping forehand which Federer can only return into the net and now it's deuce. But the Fed Express earns himself another set point when finding the angle to unleashing a cross-court winner which gives Haas no chance. Another long rallies ensures and somewhat predictably it's the German who eventually falters by hitting long. Federer now leads two sets to nil and surely this match is as good as over now.

1438 : A crushing smash at the net puts Federer 0-15 but Haas fights back with a sizzling backhand winner to finish off a long rally and bring the scores level. The next two points are shared after respective errors from each player but when Haas hits long in the next, Federer has another set point...

1433 : For the second time in this match an all too casual attempted drop shot on the baseline from Federer flops into the net. He really ought to stop doing that. Nevertheless the Swiss then gets his act together with a ruthless smash to go 40-15 up and then makes sure he wins the game. It's now 6-5.

1431 : Federer is unable to return two successive strong first-serves from Haas, who claws his way back into an advantage position. The German then has a fine opportunity with an overhead volley at the net to kill the game off but pushes it wide of the tramlines and now it's deuce. The next rally is a long one and surprisingly it's Federer who commits an unforced error by hitting it long and Haas is presented with game point. This time he takes his chance when the Swiss star once again hits his shot out and that was without doubt the most anxious he's looked all match.

1428 : Haas settles down after falling 0-15 down and initially shows no sign of buckling under the pressure. He relies on two Federer errors to move 30-15 up but a double fault restores parity in what is becoming a nervy game. After a long rally Haas then volleys into the net with a poor backhand and now Federer has set point...

1422 : Haas' cause isn't helped by the number of first serves Federer is landing - before this game he'd only missed two in this entire set. This ironically is his worst service game for some time, but still only drops one point on his way to taking a 5-4 lead. Now Haas must serve to stay in the set.

1420 : Haas tries his luck with one of those audacious through the legs shots when chasing a lob but the crowd are disappointed to see the ball find the net. This means it's 30-30 and Haas finds himself in a precarious position but he re-discovers his focus to take the next two points for 4-4.

1416 : More formidable serving from Federer results in another easy hold although Haas did at least win a point this time. The German is clearly frustrated with the impossibility to break the Wimbledon legend but he must take confidence from his plucky performance so far this afternoon.

1414 : Having worked so hard to stay in the rally, a lazy attempted drop shot from Federer hits the net and Haas leads 40-15. But the German returns the favour in the next point when an equally limp drop shot also nestles in the netting. It really was an embarrassingly poor shot. He puts it behind him and a firm forehand winner moves the set score to 3-3.

1411 : Vik Dowlul has got in touch and says: "This game is well and truly over, the Fed Express took a couple of games to get the engine stokedup, it has just had its wheels oiled and has a clear passage to destination SW19 Final. Three sets and you can stick a fork in this one. Get ready for Murray Mound!"

1409 : It's a breeze for Federer with another hold to love - in fact he hasn't even dropped a point on his serve in this set and Haas isn't getting close. If Haas is going to reach the final, I bet he'll have to win the next three sets in tie-breaks!

1407 : Haas holds again but surely Federer won't want to be taken to a tie-break again. He must find away to combat the German underdog's very strong serve.

1404 : Federer responds with a commanding service game of his own and you can't really see Haas even getting close to breaking the great Swiss.

1402 : Fresh from the disappointment of losing that tie-break, Haas is quickly back into his confident momentum on serve with a straight-forward hold.

1401 : Dami Ibironke has emailed in, saying: "I think Haas has maintained his stunning form coming from victory in Halle and I think Federer will have a really tough test. I predict a four setter game and a federer win though." Keep your views coming in to christopher.hammer@bskyb.com

1400 : It's a comfortable hold for Federer, who is supremely relaxed now on his favourite court in tennis. Can anyone really see a shock occurring?

1357 : Sure enough Haas finds the net on the next point and Federer clenches his fist as he seals the opening set. It's going to be so tough for Haas from now to cause an upset - if it wasn't hard enough already.

1356 : A blistering return from Federer helps him regain the advantage before Haas hits long to fall 3-6 down. It looks like all that hard work to get to the tie-break in the first place will all be in vain...

1355 : A stunning winner down the line from a scrampering Haas across the baseline on Federer's serve cancels out the earlier mini-break and it's now 4-3 to the Swiss.

1349 : Again, another long rally goes the way of Federer as Haas hits long in the opening point and the world number two moves 40-0 up with a cheeky floating volley at the net which leaves his opponent wrong footed. Haas' return on the next point is wide so now we have a tie-break.

1345 : It's Federer who is winning the majority of the longer rallies with Haas struggling to find the shots to finish his opponent off. However he olds his nerve with some well-placed serves to keep Federer at bay and looks intent to get on the front foot at the net. His strategy is working so far and now leads 6-5 in this opening set.

1343 : A poor backhand volley from Federer flies out of play for 0-15 although he responds with a powerful driving forehand which is too hard for Haas to get back over the net. The Swiss star moves ahead with a stunning forehand winner which beats a stretching Haas and is 40-15 up when the German hits long. Federer wraps up the game with an ace so it's now 5-5.

1340 : Haas digs deep to hold his serve again and he'll win this opening set if he can now break Federer. But that's a big if isn't it?

1338 : Ben Leach has got in touch to say: "Following you all the way from South Africa. Wanted to ask you if there is any truth in rumours that semi-final tickets for today have gone for as much as 8500 pounds? Holding thumbs for two five-set thrillers and a Murray-Federer final on Sunday." I actually have no idea how much tickets have been sold for but I'm sure if Murray makes it to the final you'd have to be a millionaire to afford one!

1335 : A wonderful lob from Federer beats a resigned-looking Haas all ends up in the opening point of this game and oh how the crowd loved it. Another winner follows for the former five-time champion and it isn't long before he ensures the set score moves along to 4-4.

1333 : It was ascorching day yesterday but thankfully from the men's point of view it's much cooler now, with plenty of cloud around to keep temperatures down. I doubt the players would have coped with a five-setter in yesterday's conditions!

1332 : Federer only has one Hawkeye challnge remaining in this first set after his latest appeal against a Haas ace is called in. The German holds to love and is looking cool, calm and composed right now.

1330 : Haas pushes Federer hard in this game, taking him to 30-30 before an untimely error puts the Swiss ace ahead. Federer finishes it off when sending Haas the wrong way along the baseline with an easy winner.

1328 : Of course if you'd like to get in touch about all things Wimbledon then the email address you need is christopher.hammer@bskyb.com

1325 : A sublime cross-court forehand winner from Federer at the baseline is the highlight from this game but it's Haas who manages to dig in and hold his serve once again.

1322 : Federer holds serve to love and you just get the impression he's now quickly working his way through the gears.

1318 : Sure enough a fine backhand winner from the baseline passes a stationary Haas at the net as Federer moves 0-15 up in the next game. Despite falling a further point behind, Haas battles back to win the next four on the bounce and keep his nose in front during these early stages.

1316 : Federer is slowly getting into his stride as he drops two points on serve in a relatively straight-forward hold. I'm sure he wont' have any nerves in comparison to Haas so we can expect to see some vintage Federer tennis pretty soon.

1313 : Haas serves first in this opening men's semi-final on Centre Court and unsurprisingly has to work hard for every point as Federer takes him to deuce. Even so he earns a warm round of applause from the crowd as he holds his nerve to take the next two points, including a confident winner at the net, to open up a 1-0 lead.

1310 : Federer holds a 9-2 lead over Haas in their head-to-head record and has indeed won the last eight meetings between the pair. However the 31-year-old veteran can boast of a five-set victory over Federer in the fourth round of the 2002 Australian Open so there's no doubt he'll hold out some hope of causing a shock today.

1300 : While we wait for the action to get under way lets look back on how both these players made it this far to the last four. Starting with Federer, well, he's had it pretty easy going so far, as expected. The Swiss star, bidding to reach his seventh straight final here at SW19, has only dropped one set and that came in his third round clash against Philipp Kohlschreiber while he took little time in brushing aside Yen-Hsun Lu, Guillermo Garcia-Lopez, Robin Soderling and Ivo Karlovic in his other games. Haas, by contrast, has had to produce some of the best tennis of his career to get to this stage and the titanic five-set thriller against Marin Cilic in round three and his quarter-final triumph over fourth seed Novak Djokovic are undoubtedly his standout moments so far. But has he got what it takes to stop the Fed Express?

1250 : Welcome to today's live commentary from Wimbledon where the men's semi-finals take centre stage. Later on today Andy Murray continues his quest to become Britain's first male Wimbledon champion since Fred Perry in 1936 as he takes on America's Andy Roddick but first it's tournament favourite Roger Federer up against surprise package Tommy Haas.