NEW YORK -- Pete Sampras met the wall of exhaustion at the U.S. Open yesterday and played on.
He played with a tightening back and blistered, peeling feet. And he played through a blur of exhaustion, in which every point he missed was like a kick to his stomach.
The man often described as colorless and bland, played with a passion that inspired cheers of "Pete! Pete! Pete!" to ring in his ears.
And in the fifth set, with Jaime Yzaga up 5-3 and within two points of victory, he played on pure guts, a crowd's insistence and his own true grit.
"I wasn't going to retire and let him not earn it," Sampras said. "I've never felt this bad, been in this bad a shape in my entire life. But no matter how bad it got, I wasn't going to quit. Just the pride of it. I thought, if he's going to beat me, he's going to have to go the distance."
It wasn't until Sampras served to Yzaga's strong backhand on match point three games later and could not reach Yzaga's cross-court winner that the merciful end came.
It was Yzaga, 3-6, 6-3, 4-6, 7-6 (7-4), 7-5, securing the classic that stretched across 3 hours, 38 minutes on Stadium Court.
Yzaga advanced to the quarterfinals, where he will meet Karel Novacek, who beat Javier Frana yesterday, 6-3, 6-3, 6-7 (3-7), 6-3.
In a late match, No. 4 seed Michael Stich beat No. 14 Yevgeny Kafelnikov, 7-6 (10-8), 6-3, 6-2. In a quarterfinal, Stich will play Jonas Bjorkman, who won, 3-6, 6-3, 6-2, 6-7 (3-7), 6-3, over Joern Renzenbrink.
"I have to thank the crowd for helping me through that fifth set," Sampras said. "I was down and they kept me going."
Sampras gathered his gear quickly at the conclusion. While Yzaga stopped for on-court interviews, Sampras hurried to the referees' office, where he was met by chief medical doctor Brian Hainline and chief internist David Cooper.
"Basically, what he has is muscle fatigue," said Cooper. "It is not a heat-related illness. He is just exhausted, an overwhelming sense of fatigue."
"I'm not in great shape," said Sampras. "I worked out and rode the bike, but it's not match conditioning. I just hit the wall today. I didn't have anything left.
"In the end, I was just going on the adrenaline from the crowd and that helped me out. But I couldn't recover after points and my feet, both of them are raw."
He called for a trainer twice, but after removing his shoes and socks did not have time to get them wrapped.
"You've got to be bleeding to get an injury time out," he said. "I didn't have any blood, just red, sore feet with the skin peeling off."
He was sore after his second-round match with Daniel Vacek and complained of sluggishness at the start of his four-set match with Roger Smith.
"I knew I was in for a pounding on the hard courts against Jaime," Sampras said. "I knew there would be a lot of long rallies, but I didn't really feel anything until all at once in the third set I
just felt like there was nothing left."
By the time Sampras got to the fifth set, he was bent over and leaning on his racket between nearly every point.
"I was just trying to catch some wind," he said. "I just couldn't get any oxygen down."
And yet Sampras and Yzaga waled at each other like bullish prize fighters. It didn't matter that Sampras' feet allowed him little mobility after the third set, he still thought he could win the long rallies. And it didn't matter that the pressure of upsetting the world's No. 1 player, who only two days ago was being called invincible, had Yzaga's heart in his throat.
"He never gave up," said Yzaga, who was within two points of victory in the fifth set three times before finally coming through. "He kept fighting. He showed what it means to be a champion -- and he almost pulled it out.
"He was so tired and I could see how tired and I thought he couldn't, he couldn't, but toward the end he was playing better and better from 5-3 to 5-4 to 5-5.
"And the people were pulling for him, but I kept my cool, kept my mind in the match and pulled it out. It is huge for me, to beat the No. 1 player in the world in a Grand Slam event."
Yzaga, who once beat a 17-year-old wild-card entry named Pete Sampras here in 1988 to advance to the second round, beat a champion by the same name yesterday and is in the U.S. Open quarterfinals for the first time in his life.
"I guess you could call it a bit of an irony," Sampras said. "I didn't feel well and the crowd was against him but he made a huge match point. You've got to give him all the credit."
Singles, fourth round Jonas Bjorkman, Sweden, def. Joern Renzenbrink, Germany, 3-6, 6-2, 6-7 (3-7), 6-3. Karel Novacek, Czech Republic, def. Javier Frana, Argentina, 6-3, 6-3, 6-7 (3-7), 6-3. Jaime Yzaga, Peru, def. Pete Sampras (1), Tampa, Fla., 3-6, 6-3, 4-6, 7-6 (7-4), 7-5. Michael Stich (4), Germany, def. Yevgeny Kafelnikov (14), Russia, 7-6 (10-8), 6-3, 6-2.