KEY BISCAYNE, Fla. (AP) -- After a succession of marathons at the Sony Ericsson Open, Roger Federer hurried into the quarterfinals.
Long matches pushed Federer's start into early Wednesday morning, and he wrapped up a victory at 1:29 a.m., needing just 52 minutes to beat qualifier Olivier Rochus 6-3, 6-1.
Federer couldn't remember ever starting a match so late. He found it odd even to be up at such an hour, given that he's the father of young twins.
"I'm getting up usually at 1:30," he said. "That's what tennis is all about. We don't know when we play, and we don't have a set schedule, and so we have to be able to adapt."
Federer took the court after Maria Sharapova earned a semifinal berth by winning a 3 1/2-hour match that ended at 12:19 a.m. She beat No. 26-seeded Alexandra Dulgheru 3-6, 7-6 (6), 7-6 (5).
Sharapova's opponent Thursday will be No. 21 Andrea Petkovic, who earlier played for nearly three hours on the same stadium court to notch her second upset in two days, beating No. 6 Jelena Jankovic 2-6, 6-2, 6-4. Petkovic eliminated No. 1 Caroline Wozniacki in the fourth round.
Two-time champion Kim Clijsters also went the distance, overcoming five match points to beat No. 19-seeded Ana Ivanovic, 7-6 (4), 3-6, 7-6 (5).
American Mardy Fish advanced to the quarterfinals, and even his victory in straight sets was grueling. Hobbled by cramps at the end, a gimpy Fish whacked a service winner on match point to beat Juan Martin del Potro, 7-5, 7-6 (5).
Winning with less duress were No. 1 Rafael Nadal and No. 2 Novak Djokovic. Nadal committed only five unforced errors and defeated No. 21 Alexandr Dolgopolov 6-1, 6-2. Djokovic extended his winning streak to 23 consecutive matches by beating fellow Serb Viktor Troicki 6-3, 6-2.
Clijsters, the tournament champion in 2005 and again last year, was serving at 1-5, love-40 when her comeback begin. Ivanovic took the loss badly.
"You should see my racket," Ivanovic said, managing a smile. "I kind of broke my racket, and then kind of cried a little bit, and then I was OK."
Sharapova won despite 17 double-faults and twice as many unforced errors as Dulgheru.
"It was long. It was tough," she said. "It was not my best performance, but, you know, I gutted it out till the end."
Sharapova turned her ankle late in the third set and required treatment from a trainer in the middle of a game. The crowd gasped when her misstep was replayed on the video scoreboard, but the injury didn't appear to affect her.
"It hurt when I did it," she said. "I iced it a lot, and did an ice bath and got it taped. I think I'll be OK. I'm tough."
When John Isner lost, Fish became the lone U.S. player among the 16 male and female quarterfinalists. At 29, he'll overtake Andy Roddick and become the top-ranked American man for the first time if he defeats No. 6 David Ferrer on Wednesday.
"Being the No. 1 American would be something that would be pretty cool to tell my kids about," said Fish, who is married but not yet a dad.
The U.S. men's rankings face a possible shake-up because Fish's longtime friend Roddick lost his opening match last week and is expected to drop from eighth to about 15th, the lowest he has been since 2002.
By contrast, Fish's fortunes are on the rise. He's ranked a career-best 15th and is into the Key Biscayne quarterfinals for the first time in his 12-year career.
"I've got some time still, and still feel relatively young - although I probably won't tonight," said Fish, healthy now after battling frequent injuries. "I've had some years where I haven't played very many matches, and I'll hopefully get those on the back end."
He and del Potro both looked weary at the end of their 2 1/2-hour slugfest in humid, 85-degree sunshine. When Fish began cramping in the tiebreaker, he knew he needed to avoid a third set.
"I was very lucky - I would not have recovered," he said. "I was struggling just to serve there that last point."
Ferrer will be a handful. He topped Marcel Granollers 6-1, 6-2 and has lost only 12 games in three matches.
Isner, seeded 30th, lost to Kevin Anderson 6-3, 7-6 (4). Anderson's reward will be a chance to end Djokovic's winning streak Wednesday night.