Two days after playing a marathon come-from-behind match that lasted well into the early morning hours, Todd Martin was back under the lights at the U.S. Open tonight, playing in the quarterfinals against Slava Dosedel. And he was still exhausted.

"I practiced a couple of times yesterday to get back into the swing of things, and I felt terrible," he said. "And then today when I practiced, I don't think I could have felt any worse. I hit for a half-hour and was really spent. I told my trainer, Todd Snyder, that I was pooped and didn't know how I was going to play, but fortunately, adrenaline kicked in."

Martin rode a wave of emotion through the hard-serving match, rising, then falling, then rising again until he finally emerged with a 6-3, 5-7, 6-4, 6-4 win that hurtled him into the semifinals against Cedric Pioline. The unseeded Pioline withstood a serving battle of his own today, breaking No. 5 seed Gustavo Kuerten's serve only once in a tiebreak-filled match that finally ended at 4-6, 7-6 (8-6), 7-6 (16-14), 7-6 (10-8). Pioline has a 5-3 edge on Martin in their head-to-head matches, although Martin has won three of the past four times they have played.

"I need to get some rest, get some treatment and come out Saturday firing," Martin, 29, said. "Cedric's a great player and he played the best I've ever seen him play today. That was one of the best tennis matches I've ever watched, so hopefully we'll have a good old-man battle there."

Pioline, 30, certainly looked strong today, especially at the net, where his backhand volleys cut sharp angles out of Kuerten's side of the court. Coming into the match, he was officially the underdog against Kuerten, who won the 1997 French Open. But much of Kuerten's success has come on clay, while Pioline has been the runner-up both here and on the grass courts of Wimbledon. He has looked sharp throughout this tournament, upsetting No. 14 seed Tommy Haas in the fourth round.

It also hasn't hurt that both he and the seventh-seeded Martin have been playing in the half of the draw that was decimated early by the loss of top-seeded Pete Sampras and two-time defending champion Patrick Rafter, both of whom departed with injuries. Still, despite the loss of the strong seeds, the quality of tennis has been high. The match between Pioline and Kuerten turned only on just a few key points, with each tiebreaker having the chance to go to either player.

The 30-point tiebreaker at the end of the third set was particularly thrilling, with Kuerten getting a great chance to take the set at 9-8. But Pioline hit an unbelievable passing shot to even the score, falling on his back as he stretched his racket. When he saw the ball bounce true, he started waving his arms and legs in the air like an overturned turtle.

Kuerten's reaction was equally grandiose -- he dropped his racket in amazement and then threw his hands up in the air. Then as Pioline was getting up off the ground, Kuerten walked all the way around the net to Pioline's side of the court, shaking Pioline's hand to congratulate him on such a well-played stroke.

"I was very surprised -- that's not usual," Pioline said later, laughing. "I just stood up and turned and he was there, shaking my hand. I was like, `What's going on -- are you stopping or what?' But I think he just wanted to congratulate me for the shot."

Pioline said he was headed back to his hotel room to rest after playing in the humid conditions at the tennis center, something the fragile Martin will be doing as well. But Kuerten will be heading back to pack his suitcase, something that disappoints him despite the quarterfinals being his best showing here. His 23rd birthday is Friday, and he would have loved to give himself the semifinals as a present.

"Today I am 22 still and I thought I had more of a chance today because I was younger," Kuerten said. "I'm sure I'm wrong now, because tomorrow I would have more experience, and it would be different.

"But it's like this. If we don't have these moments, we cannot celebrate wins, too. Next time, I hope to be a little more lucky."

U.S. Open Notes: On Wednesday, Richard Krajicek was told he set an all-time record by serving up 48 aces in his 7-6 (7-0), 7-6 (7-4), 3-6, 1-6, 7-6 (7-5) loss to Yevgeny Kafelnikov. In fact, he served 49 aces, a fact caught after the referee's office reviewed a tape of the match. . . .

Midway through his quarterfinal win on Wednesday, Andre Agassi let out a frustrating grunt after getting what he felt was a bad line call. Instead of yelling at the chair umpire, however, Agassi walked calmly to the side of the court and made a request. "Just look at that one on tape later and then call and apologize," he said. "That's all I ask.". . . . The U.S. Open's first trophy was handed out today when Japan's Ai Sugiyama and India's Mahesh Bhupathi won the mixed doubles title, defeating Americans Kimberly Po and Donald Johnson, 6-4, 6-4.