Liverpool held their nerve where others have fallen apart to reached the FA Cup semi-finals.

Their own Treble dreams were kept alive as brave, defiant Tranmere went out of a tournament they have graced with their own special brand of fantasy.

And the most relieved man on the park must have been Robbie Fowler, whose horror mistake had gifted Tranmere a lifeline. It ended with the Liverpool skipper driving home the penalty that finally broke Rovers' hearts.

But there had been so much more to this compelling game. Liverpool had led 2-0 at the break and 3-1 soon after. But Tranmere just would not give in.

The spectre of those heroics against Southampton last month when a 3-0 lead for the Premiership side was turned into a 4-3 Rovers victory, hung over this Mersey battle.

Liverpool were forced to defend with their lives as Tranmere launched another blitz. But Liverpool just about held on - and were eternally grateful to Fowler for that late penalty after the England striker had caused them so much heartache with a ridiculous back pass that gave Tranmere hope and the will to keep fighting.

But when the dust had settled, Liverpool were in their first FA Cup semi-final for six years, with the Worthington Cup already won and a great chance to reach the UEFA Cup last four when Porto come to Anfield on Thursday.

Tranmere were left with pride, knowing they had not been outclassed or outfought, and must hope they can carry this sort of performance into the battle against relegation.

The expectancy was there for Rovers, the noise and the flags for Birkenhead's finest, but Tranmere were taking on history at Prenton Park.

They had never beaten Liverpool in their history and such has been the division between the sides that just one League Cup tie in 1979 and an FA Cup meeting in 1943, both won by the Anfield men, had been their only chances to bridge the Mersey divide.

Rovers recalled Paul Rideout, hat-trick hero from the last-round win over Southampton, in place of transfer-listed Wayne Allison while Graham Hinds took over from cup-tied Micky Mellon.

Liverpool were without injured Stephane Henchoz and Christian Ziege as well as suspended Dietmar Hamann, and brought in England Under-21 full-back Steve Wright.

Markus Babbel moved to the centre of defence, while Gary McAllister, Danny Murphy and Nick Barmby came in from the side that drew in Porto on Thursday, Vladimir Smicer dropping to the bench. Emile Heskey was not even in the squad with a minor back injury.

By half-time Liverpool were in reasonable control, but then Southampton thought that on this field of dreams last month!

Tranmere's approach was as normal for these occasions. They tried to impose their aggressive, aerial style from the start.

It had stunned seven previous Premiership sides, and Liverpool looked uncomfortable and unsteady against the expected war of attrition.

They weren't clearing their lines properly, the ball just kept being launched back at them and Tranmere were getting plenty of early encouragement.

But with their first serious attack on 11 minutes, Liverpool were ahead. Sander Westerveld's long clearance reached Michael Owen deep on the left.

His cross was met by Murphy on the edge of six-yard box, and the downward header - under no real pressure - bounced down and away from John Achterberg and into the net.

The goal took the sting out of Tranmere's play, especially as they were being confronted with a no-nonsense, hard tackling Liverpool midfield.

Steven Gerrard, in particular, was a defiant, determined young man, winning possession and spraying passes.

After Tranmere's early flurry, the influential Gerrard began to have an affect on the proceedings, and Liverpool started to play the game in Rovers' half rather than their own.

On 27 minutes they went two up. Sammy Hyypia's long ball out to the right found Murphy unmarked and in space again, his instant pass in behind the defence saw Owen sprinting clear - looking a foot offside - but given the chance he cooly slipped the ball past Achterberg.

The game was an interesting reunion of Liverpool's FA Youth Cup-winning side of 1997, Gareth Roberts and Andy Parkinson now with Rovers plus the Liverpool trio of Owen, Murphy and Jamie Carragher.

But the tackles were still flying in among old pals!

Rovers switched Parkinson from right to left wing, because he was getting little joy while Liverpool slowly took a grip on the game.

Mind you, considering how Tranmere hit back from 3-0 down in the last round, there could not be any complacency.

Barmby had a decent chance to make it three when Robbie Fowler's clever pass put him in space on the right of the box, but Achterberg raced from his line to save well at the England man's feet.

Referee Alan Wiley dished out a lengthy warning to Rideout for the third offence with his elbows, and then angered Liverpool by booking Gerrard for a late challenge on Roberts on 41 minutes.

Such was Liverpool's professional control at this stage, that Tranmere's first shot came on 44 minutes when Jason Koumas sent a 25-yard free-kick curling wide of a post.

Koumas then crashed in another long-range kick seconds before the break to remind Liverpool that this was not all over yet.

The last thing Liverpool needed was to give Rovers the slightest hint of incentive after the break, but within a minute of the restart John Aldridge's boys had pulled a goal back and the tension and passion level was instantly revved up.

Koumas' long ball in from the left was met by Steve Yates beyond the far post. The defender, who had scored twice to knock out Everton earlier in the tournament, saw his header hit the post, clip a desperate Westerveld and then fly into the top corner.

Three minutes later Graham Allen was booked for a bodycheck on Owen, as Liverpool sought to hit back and keep their nerve.

Liverpool's response was commendable. Seven minute after Tranmere's initial ray of hope, the two-goal advantage was restored. McAllister's corner was flicked on by Babbel for Gerrard to power home a close-range header.

Tranmere undone by a set-piece was certainly an irony!

But they just refused to throw in the towel - it's not in this club's nature where cup combat is concerned. Allison was now thrown into the fray in place of Rideout and there was little doubt that the aerial combat was going to be increased.

But a minute after his introduction, Fowler's suicidal involvement put Tranmere back into the game. The Liverpool skipper decided to run back towards his own goal and try to thread a backpass through players.

It never reached Westerveld. Babbel got in the way and the ball broke for Allison to drill delightedly past the Dutch keeper. The long throw man, Dave Challinor, was now on in place of Richard Jobson, the intent now even more obvious.

Nick Henry was booked for a foul on Barmby, Liverpool desperately trying to regain their control. For those who have witnessed this before, it's easier said than done.

Igor Biscan's muscle was introduced in place of a limping Barmby, Liverpool were living on their nerves now, and the ball was forever bombing into their box.

McAllister set up Fowler on 70 minutes, but he wasted a chance to redeem himself, Achterberg saving well.

But with 10 minutes left, Liverpool got their fourth and Fowler made up for that dreadful error.

McAllister broke on the left, cleverly waited until he got into the box and cut between two defenders. Yates' brought him down, Roberts was booked for protesting, but Fowler coolly drilled home the penalty.

Still Tranmere came back, but it took a good save from Achterberg to hold a Fowler header after a lightning break from defence.

Smicer for Murphy and Jari Litmanen for Owen helped run down the clock for Liverpool, and after four minutes of injury time the relief was clear from all in red, as Tranmere went out with their pride and heads held high.

Tranmere: Achterberg, Hinds, Allen, Jobson (Challinor 60), Yates, Parkinson, Henry, Koumas, Roberts, Rideout (Allison 57), Barlow.

Subs Not Used: Murphy, Scott Taylor, Morgan.

Booked: Allen, Henry, Roberts.

Goals: Yates 47, Allison 58.

Liverpool: Westerveld, Babbel, Wright, Hyypia, Carragher, Barmby (Biscan 66), McAllister, Gerrard, Murphy (Smicer 83), Fowler, Owen (Litmanen 87).

Subs Not Used: Arphexad, Vignal.

Booked: Gerrard.

Goals: Murphy 12, Owen 27, Gerrard 52, Fowler 82 pen.

Att: 16,342

Ref: A Wiley (Burntwood).