NEEDING ALL HIS PERSONAL-BEST 39 ACES, Federer finally beat Tipsarevic 6-7 (5), 7-6 (1), 5-7, 6-1, 10-8. -- PHOTO:BLOOMBERG NEWS

There was never a let-up in the tension as Federer was forced repeatedly to rally from behind before outlasting 49th-ranked Janko Tipsarevic 6-7 (5), 7-6 (1), 5-7, 6-1, 10-8 yesterday.

The hard-fought victory carried the defending tennis champion into the fourth round.

Tipsarevic, who has never reached a singles final, played the match of his life. He gave the world No 1 everything he could handle with the packed crowd screaming on every point.

'I went on court with the idea that I could win,' the Serbian player said. 'I was close. I lost because he was better in the important moments of the match.'

Federer, seeking his 13th Grand Slam crown, needed every one of his personal-best 39 aces - 14 more than his previous mark in one match - to fend off the 2001 Australian Open junior champion.

'I don't often get to play five-setters unless they're against Nadal at Wimbledon,' Federer said of his rivalry with long-time No2-ranked Rafael Nadal.

'It was good to be part of something like this. It's a pity you can't have draws in tennis.'

The Swiss beat Nadal in five sets in the Wimbledon final last year.

Federer has reached the finals of the last 10 Grand Slam events, winning eight of them and losing two to Nadal - both at the French Open.

Yesterday, Federer had numerous chances to take control. But Tipsarevic saved 16 of 20 break points against him until Federer finally cashed No 21 after rallying from 0-40 as the Serb served at 8-8 in the fifth set.

'I had to block out all the chances I missed,' said Federer, who next faces No12 Tomas Berdych, a four-set winner over No21 Juan Monaco.

'He came up with some fantastic plays and played me well.'

Tipsarevic, a bookish Serb who reads Russian classics in his spare time, said his strategy was simple.

'Be aggressive, and then try to make him work for the points that he's winning,' he said.

'Against Roger it's so hard, because he's playing every point. Even when you're up like 40-0, the game is far, far from over.'

James Blake, seeded 12th, came back from two sets down, then from a double break in the fourth before beating veteran Frenchman Sebastien Grosjean 4-6, 2-6, 6-0, 7-6 (5), 6-2.

'That's got to be my biggest comeback,' Blake said. 'Couldn't have been a better feeling.'

It kept alive American hopes after Sam Querrey fell to No3 Novak Djokovic 3-6, 1-6, 3-6.

Seventh-seeded Fernando Gonzalez, who lost the final here last year to Federer, was ousted 2-6, 7-6 (4), 3-6, 1-6 by Croatia's Marin Cilic.

Cilic, who had never gone past the first round in three previous majors, called it his best performance. He faces Blake next.

Two of Russia's top 10 women - No2 Svetlana Kuznetsova and No6 Anna Chakvetadze - were also ousted.

Kuznetsova was beaten 3-6, 4-6 by 18-year-old Agnieszka Radwanska of Poland and Chakvetadze lost 7-6 (8-6), 1-6, 2-6 to Maria Kirilenko.

As she did in her last match, eighth-ranked Venus Williams started slow but still ousted No31 Sania Mirza 7-6 (7-0), 6-4.

Mirza broke early and served for the first set at 5-3, only for Williams to break back. The Indian star fended off two set points while serving at 5-6 to force a tiebreaker, where Williams was at her best, refusing to drop a point.

Williams had five aces in the second set, dropping only seven points in five service games. She broke Mirza to pull ahead at 4-3, then held serve the rest of the way.

AP