TENNIS/AUSTRALIAN OPEN CHAMPIONSHIPS:ROGER FEDERER survived an almighty scare yesterday to book his place in the quarter-finals in Melbourne. Federer needed almost three-and-a-half hours to overcome a dogged Tomas Berdych 4-6, 6-7 (4-7), 6-4, 6-4, 6-2.

The second seed will now play Argentine Juan Martin Del Potro, seeded eighth, who had a more convincing 5-7, 6-4, 6-4, 6-2 win against 19th-seed Marin Cilic, of Croatia. Andy Roddick, the seventh seed, is also through to the last eight after a 7-5, 6-1, 6-3 win over Spain’s Tommy Robredo, the 21st seed.

Federer looked in serious danger of failing to reach the quarter-finals of a grand slam for the first time since the French Open in 2004. But he dug deep and showed all the experience of a 13-time grand slam champion to get past Berdych. There were 11 breaks of serve in the match, with Federer hitting 61 winners to the Czech’s 58. Berdych also had two more unforced errors than his Swiss opponent who made 40. But the most telling difference was the number of aces by each man with Federer firing down 20 and Berdych just eight.

Federer got off to a poor start, dropping his serve in the opening game. He was broken again in the fifth and although he got back to 4-3, Berdych had the opportunity to serve out the set which he did.

The second set was much tighter and it was Federer who got the early advantage to take a 2-0 lead. But Berdych rallied for 2-2 and with no more breaks of serve it went to the tiebreak which the 20th seed eventually took with a simple volley winner for a two sets to love lead. Federer got the vital breakthrough of the third set in the seventh game to go 4-3 up and at 5-4 ahead and serving for the set he clinched it with an ace.

Again the start of the fourth set produced another break of serve, this time Federer getting out to an early 3-1 lead. After Berdych took a medical time-out for some treatment to his hamstring area he rallied back to 5-4 and three break points up on the Federer serve. But he could not capitalise on them as Federer clinched the set at the second opportunity.

The world number two raced out to a 5-2 lead in the final set as Berdych started to falter but he made a meal of his final game wasting two match points, then giving Berdych the opportunity to break with a wide forehand shot and a double fault before two aces – his 19th and 20th of the match – sealed a thrilling win.

Federer said there was no sense of panic when he went down two sets. “I wasn’t thinking of losing, that’s for sure,” he said. “The finish line was still very far for Tomas. I knew that. I kind of felt after a terrible first set from my side that if I probably want to win this it’s going to go to five sets.

“That’s why I kind of was prepared for five from the start. I think that’s what made me be so determined towards the end. I believed in it all the way, and I think that was key in the end.”

Del Potro, at 20 the youngest man in the top 10, had less difficulty against Cilic and after handing him the first set with a double fault, he was far less giving in the remainder of the match. In the seventh game of the second set, Del Potro made the decisive move to bring up his only break point of the set, which he then served out 6-4.

The momentum was with the 20-year-old as he moved into the third set but he was made to wait until the 10th game to get himself in front. The fourth set was routine for Del Potro, who broke Cilic in the fifth and seven games to serve out the match.

Roddick stretched his run of victories against Robredo to 10 consecutive matches with his win. A netted forehand by the Spaniard gave the American the opening set and from there it was plain sailing for Roddick, who fired 13 aces past his opponent and 34 winners.

Roddick will play the winner of the night match between Novak Djokovic and Marcos Baghdatis.

Meanwhile, Andy Murray’s momentum is building nicely, the 21-year-old Scot overcame illness to thrash Jurgen Melzer 7-5 6-0 6-3 on Saturday and now faces another left-hander in Spain’s Fernando Verdasco, who had a similarly comprehensive 6-4, 6-0, 6-0 win over a lacklustre Radek Stepanek.

The world number four, chasing a maiden grand slam title, has not dropped a set so far after an aborted first round against Andrei Pavel – when the Romanian retired with a back problem – and a comfortable 6-4, 6-2, 6-2 victory against Marcel Granollers.

After that win, Murray spent Friday in bed with a headache and sore throat but you would never have known, such was his Dminance over Melzer. “I didn’t feel terrible,” Murray said. “I’m sure by the next match I’ll be feeling fine.”

The British number one’s triumph over the Austrian stretched his winning run against left-handers to 21 matches.

The only left-handed player he has lost to (five matches) is Rafael Nadal – the world number one, top seed in Melbourne, and the man he is on a collision course to meet in the semi-finals.

As for Verdasco, who is ranked 15 in the world, Murray has beaten him five times – the first win coming in the second round at the Australian Open in 2007 and the last at the ATP Master Series tournament in Paris last year.

“Against Verdasco, it’s very important to use my head. I have a very good record against left-handers. The only one I’ve lost to on the tour has been Nadal,” Murray said. “I need to use my head, make him (Verdasco) do a lot of thinking and moving. If I play like I did (against Melzer), I can definitely win that one.”

Verdasco has been in scintillating form, dropping just 12 games in his three matches to date.