Lleyton Hewitt took things a step further. The Aussie set a record for the latest finish for a day's play at a Grand Slam. He beat 2006 runner-up Marcos Baghdatis 4-6, 7-5, 7-5, 6-7 (4), 6-3, completing the marathon at 4:33 a.m. local time Sunday.

Hewitt and Baghdatis went on court at 11:47 p.m. Saturday, the last scheduled match at Rod Laver Arena on Day 6, and Hewitt ripped a forehand winner on his fifth match point 4 hours, 45 minutes later.

There was never a letup in the tension. Starting when Federer was forced to rally before outlasting 49th-ranked Janko Tipsarevic 6-7 (5), 7-6 (1), 5-7, 6-1, 10-8 to reach the fourth round of the tournament he has won the last two years.

That pushed back the night session two hours.

Venus Williams beat Sania Mirza in straight sets in the first night match. Then Hewitt was up two sets to one and 5-1 in the fourth when things started to go wrong. He wasted one match point in the eighth game of that set and three more in the ninth game of the fifth before he broke Baghdatis to finish off the day.

"It wasn't easy for both of us. Obviously, an incredible day of tennis. For Roger Federer to go five sets, how often does that happen?" Hewitt said. "It's tough for everyone. Marcos and I are in the same boat."

Hewitt next plays No. 3 Novak Djokovic, who beat American Sam Querrey 6-3, 6-1, 6-3. Djokovic, the U.S. Open finalist, is Serbia's highest-ranked player.

Tipsarevic, who has never has reached a singles final, could be closing the gap on him after playing the match of his life and gave Federer everything he could handle with the packed crowd screaming on every point.

"I went on court with the idea that I can win," the Serbian 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 each 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, referring to his rivalry with No. 2 Rafael Nadal. "It was good to be part of something like this. It's a pity you can't have draws in tennis."

He 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.

Federer was untouchable in his first two matches, dropping only six games in six sets. He 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 40-0 as the Serbian served at 8-8 in the fifth set.

"I had to block out all the chances I missed," said Federer, who next faces No. 12 Tomas Berdych, a four-set winner over No. 21 Juan Monaco. "He came up with some fantastic plays and played me well."

Tipsarevic said his strategy was simple.

"Be aggressive, and then try to make him work for the points that he's winning. "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 down two sets, 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."

No. 7 Fernando Gonzalez, who lost the Australian final last year to Federer, was ousted 6-2, 6-7 (4), 6-3, 6-1 by Croatia's Marin Cilic, who had never gone past the first round in three previous majors. Cilic, who called it his best performance, faces Blake next.

Two of Russia's top 10 women also were ousted.

No. 2 Svetlana Kuznetsova was beaten 6-3, 6-4 by 18-year-old Agnieszka Radwanska of Poland and No. 6 Anna Chakvetadze lost 6-7 (6), 6-1, 6-2 to No. 27 Maria Kirilenko.

Fourth-seeded Ana Ivanovic reached the fourth round with a 6-3, 6-4 victory over No. 28 Katarina Srebotnik.

As she did during her last match, eighth-ranked Williams started slow but played her best when she needed it most in beating No. 31 Mirza 7-6 (0), 6-4.

Mirza broke early and served for the first set at 5-3, only for Williams 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 when she dropped only seven points in five service games. She broke Mirza to pull ahead at 4-3, then held serve the rest of the way.

While a few Serbian flags were scattered about the arena — the roof was closed because of rain that postponed matches on outside courts — Federer fans dominated, including one holding a sign reading "Federer Express."

The Swiss star was nearly derailed before extending his winning streak at Melbourne Park to 17 matches, tied for fourth-best behind Andre Agassi's record of 26 in a row.

Federer, who last lost a set in this event while beating Baghdatis in the final two years ago, started in top form again, ripping seven aces in his first four service games. But the Serbian, looking like a grad student in his dark-rimmed glasses and short beard, forced a tiebreaker, where the only point that went against serve came with Federer facing set point at 5-6. Tipsarevic ripped a forehand crosscourt pass that dropped just inside the corner.

Tipsarevic fended off five break points in the second set before faltering in the tiebreaker. Tipsarevic rallied from 15-40 while serving at 4-5 in the third set, then broke in the next game as Federer lost two aces to successful challenges by Tipsarevic, who then held for the set.

As he has done so often, Federer seemed to find an extra gear, running off five straight games to take the fourth set and even the match.

Tipsarevic saved two break points while serving at 2-2 in the deciding set, then a match point at 8-8 before Federer nailed a backhand volley winner to take the last break. Federer held for the match when Tipsarevic netted a backhand to end it in 4 hours, 27 minutes.

Federer shouted in relief as he pumped his fist.