Defending champion Roger Federer reached the fourth round at Wimbledon with a straight-sets victory over Marat Safin.

Federer was beaten by the Russian in the 2005 Australian Open semi-finals but there was no sign of a repeat of that result as the top seed cruised through the first two sets.

Safin began to play in the third set, which went with serve, but by that stage it was already too late and some erratic shots in the tie-break allowed Federer to close out a 6-1 6-4 7-6 win.

Federer later admitted that despite going into the match with 50 consecutive wins on grass under his belt, he had been nervous.

"I get very nervous before a match like this," the Swiss said. "He is a former world number one and has won Davis Cup which I haven't done. I admire his serve and have had tremendous battles with him.

"It was such a big occasion for both of us. For me, to prove I am number one and for him to prove he can still be number one.

"I don't know that I played phenomenal. I just played the right way, did what I had to. He was quickly down two sets to love and I played a great tie-break."

Safin said he expects Federer to lift the title a week on Sunday.

He said: "I don't see anybody who can hurt him. They know about how to play him but they don't have enough weapons to beat him.

"But it was the first time I have played on Centre Court for many years. It took me two sets to get used to it."

Next up for Federer is a meeting with Tommy Haas, the 13th seed, who came from a set down to win in four against Dmitry Tursunov.

In the upset of the day, former champion Martina Hingis crashed out at the third-round stage, losing in straight sets to Laura Granville.

Hingis had not played for a month before coming to SW19 because of injury but after having had to fend off match points against Briton Naomi Cavaday in her opening match, she seemed to regain some of her sharpness in her second-round win over Aiko Nakamura.

However, Granville never looked back after securing an early break of serve as she recorded a 6-4 6-2 victory.

The unseeded American needed to fend off three break points early in the second set as Hingis briefly rallied but once that was achieved she cruised to victory as the famous 'Champions' Graveyard' - Court Two - claimed another victim.

Hingis admitted she never got into the match, saying: "She started off well and served very well and made it hard for me. I didn't have too many chances on her serve.

"I felt everything I missed in the first set was by a couple of inches and

your confidence goes down."

Hingis admitted she was still struggling to overcome her injury but insisted she had no regrets over her decision to compete at Wimbledon.

"I see this as definitely a success, coming through a couple of rounds,'' she said.

"The draw was quite open, I wish I had done better. But I'm happy that I'm getting healthy again, that's the most important thing.''

It was also a bad day for men's fifth seed Fernando Gonzalez who squandered match point before being dumped out by Janko Tipsarevic.

The Australian Open runner-up served for the match at 5-3 in the final set and then missed match point on Tipsarevic's serve at 6-5 before falling to a 6-3 3-6 6-3 4-6 8-6 defeat on Centre Court.

In what was always a see-saw match, Tipsarevic had points for a double break at 2-0 in the final set but lost four games in a row before Gonzalez missed his opportunities.

On match point Gonzalez was not allowed to play his favoured forehand and a tentative exchange saw him slice a backhand into the net.

The Chilean would not win another game as Tipsarevic completed a famous win.

Tipsarevic's next foe will be be Juan Carlos Ferrero after the former French Open champion knocked out ninth seed James Blake, coming from a set down to win in four.

Meanwhile Paul-Henri Mathieu's fine season continued as he took out 15th seed Ivan Ljubicic.

The Frenchman, who famously squandered a two-set lead in the Davis Cup final back in 2002, has enjoyed some fine results this year and few have been more impressive than his four-set win against Ljubicic.

Mathieu stormed back after losing the first set to post a 4-6 7-5 6-2 6-3 victory.

He will now play Andy Roddick, the two-time runner-up coming through an evening tussle with Fernando Verdasco.

Roddick's big serving carried him through the first two sets with ease but he had to fight back from a break down in the third before securing a 6-3 6-4 7-6 (7/2) win.

Richard Gasquet (12) will play wild card Jo-Wilfried Tsonga for a place in the last eight after they enjoyed straight-sets wins over Edouard Roger-Vasselin and Tim Henman's conqueror Feliciano Lopez respectively.

Tsonga, who beat Lleyton Hewitt at Queen's Club recently, is only the sixth male wild card in the Open era to reach the last 16.

Justine Henin's serene progress through the ladies' draw continued despite an early start.

The top seed and world number one lost just seven games in winning her first two matches, and third-round opponent Elena Vesnina provided similarly weak resistance on Court Two.

Henin shrugged off a rain delay of around 80 minutes to cruise to a 6-1 6-3 victory and book her place in the last 16 where she will face Patty Schnyder.

The 15th seed produced another battling display, coming from 3-0 down in the final set to defeat Alona Bondarenko 6-4 3-6 8-6.

It was her third three-set win in as many matches at this year's tournament.

French Open champion Henin is chasing a career Grand Slam at Wimbledon - she would be only the 10th woman to achieve the feat - but is playing it cool with regard to her title ambitions.

"I still believe I can do it, but it's not an obsession for me," she said.

"I don't think that much about it. I just want to enjoy every moment. I enjoyed my match a lot today. I don't have anything to prove to anyone. I know how well I can play. I know my results in the past.

"This way I don't lose that much energy. Yeah, it would be an amazing achievement, but dreaming of that is not going to help me."

Serena Williams remains on course for a last-eight showdown with Henin after a quickfire win over Milagros Sequera.

The two-time former champion needed just 43 minutes to power past the Venezuelan 6-1 6-0 in what was an embarrassingly one-sided encounter.

"I was at about a six or a seven (out of 10) today," said Williams, who added her recent hamstring problem was no longer troubling her.

"Just a steady pace. Peaking at the right times, playing the big points well.

"It was going to be down to me to win or lose the match. That's I think what it boiled down to."

Williams now meets Daniela Hantuchova, who came from behind to beat Katarina Srebotnik 2-6 6-3 6-4.

Third seed Jelena Jankovic was given a fright by Lucie Safarova but prevailed 5-7 7-6 (7/4) 6-2.

The Serb had to serve to stay in the match in the second set but held firm and won the tie-break before running away with the decider as Safarova struggled with a knee problem, winning the last four games to set up a meeting with Marion Bartoli, who enjoyed a straight-sets win over Shahar Peer.

Russian star Anna Chakvetadze was not so fortunate as she became the highest-seeded ladies' casualty of the tournament so far.

The eighth seed crashed out 7-6 (10/8) 6-7 (5/7) 6-2 to Michaella Krajicek in a marathon encounter out on Court 13.

Krajicek will be the next opponent for giantkiller Granville.