At the end, they cried. Each found a shoulder and wept, one for joy, the other in despair, and both from sheer exhaustion.

For just under three hours on the muggiest day of the U.S. Open to date, Pam Shriver and Steffi Graf had fought, trading winners and cries of anguish. Graf, less than three months past her 16th birthday, finally won, 7-6 (7-4), 6-7 (4-7), 7-6 (7-4).

The Graf-Shriver match was the highlight of an otherwise desultory day. On the men's side, Mats Wilander and John McEnroe moved into the semifinals easily, Wilander defeating fellow Swede Anders Jarryd and McEnroe eliminating yet another Swede, Joakim Nystrom.

Jarryd retired because of heat prostration with Wilander leading, 2-6, 6-2, 5-0. Despite losing five straight games in the third set, McEnroe had little trouble with Nystrom, winning, 6-1, 6-0, 7-5.

Graf's dramatic victory put her into a Friday semifinal against defending champion Martina Navratilova, who continued her apparently inexorable march to the final today with a 6-2, 6-3 rout of Zina Garrison. Navratilova took a quick shower and proceeded to the Grandstand Court to watch Shriver, her friend and doubles partner, struggle with the blond youngster from West Germany.

In the midst of Boris Becker-mania, the rise of Graf to No. 11 in the women's world has gone almost unnoticed. Like countryman Becker, Graf is precocious, physically and mentally, and outgoing. She gestures and talks to herself throughout a match.

And like Becker, she has great staying power, something she put on display today, fighting back after losing a second-set tie breaker and after falling behind, 4-1, in the last set.

"At 4-1 down, I thought it would be very tough for me to win," Graf said. "But I think Pam got a little tired and I just kept going for shots and trying to win."

When Shriver finally pushed a low, reaching backhand just deep in the last of the three tie breakers, Graf let out a shout. Shriver slowly gathered her weary body, graciously put an arm around her opponent and sat in her chair, a towel over her head, weeping.

"My effort couldn't have been any more than it was," she said later. "I just think it was one of the most unbelievable matches that I've been a part of. I don't think I've ever put in such an effort and still lost in my life."

It was the first women's match in the 16 years the Open has used the tie-breaker system that went the maximum 39 games. Shriver lost a match that kept the Grandstand Court crowd in suspense until the final shot.

But for Shriver, it was a loss, and a devastating one. "It's nice when people pat you on the back and say, 'Great match, great fight,' but that's a very mild consolation because I don't think I've ever gone into a match wanting to win so much in my life. I mean, I haven't played the semifinals in a major tournament in almost two years. At least this time I didn't fall short because I did something wrong."

Neither player did very much wrong in this match. The women's players talk about Graf, even more than Gabriela Sabatini, as the next dominating player. Right now, she is one-dimensional, a superb ground-stroker who would sooner stand on her head than come to net.

But when she is dusting lines with those strokes as she did today, Graf can play with anyone in the world short of Navaratilova and Chris Evert Lloyd. Today, her buzzing forehands and backhands had Shriver lunging and flailing.

"When I was warming up this morning, my backhand was not too good," Graf said. "But in the match, I was surprised because I was hitting so many good shots. My father told me before the match to slice my backhand, and it worked very well for me."

From the beginning, it was apparent that Graf, who lost a three-set match to Shriver at Wimbledon, was primed for an upset. She broke Shriver in the first game, winning it with the first of many sliced backhands.

Shriver got that break back, charging the net at every opportunity and daring Graf to pass her. Often, Graf did. But Shriver, using her height (6 feet) and reach, gobbled up any ball that wasn't perfect and kept the match taut throughout.

"Some of the points out there were violent for me, the way she was hitting the ball," said Shriver, who had trouble sitting after the match because of leg cramps. "The points were a lot like at Wimbledon, only there I had the advantage of it being grass so she didn't get as much bounce."

Graf had a chance to win the first set when she broke Shriver to lead, 6-5, but lost her serve in a classic seven-deuce game in which Graf saved six break points and Shriver saved two set points.

Shriver won the game when Graf netted a low backhand, and so they went to the first tie breaker. Quickly, Shriver took a 3-0 lead, but Graf hit three winners to even it, took a 4-3 lead when Shriver netted a backhand and then hit a hard backhand return to lead, 5-3. At 6-4, she hit a backhand on the line and had the first set.

"It would have been easy for me to lose heart after that set because it was hot and the set was so tough," Shriver said. "But if I had lost concentration, I would have been down, 4-1, in a hurry."

Instead, she broke Graf for 2-1 in the second set, only to be broken back when serving for the set at 5-4. So, again they went to a tie breaker. This time, it was Shriver who made the big shots, coming from 3-1 down to a 6-3 lead. At 6-4, Shriver twisted a serve that Graf reached for and netted and it was one set each.

"I had to tell myself it was a start again, not the end," Graf said. "But she was volleying very well then."

Shriver quickly volleyed her way to a break at 3-1, causing Graf to slam a ball in frustration while she muttered obscenities in German, according to German-speaking observers.

Graf may have been frustrated, but she wasn't finished. She survived a deuce game on her serve in the next game and broke back back with a powerful forehand.

"Up, 4-1, I was so close to having the match," Shriver said. "But she kept coming up with unbelievable shots on the big points. At deuce on 4-1, she comes up with a great serve. She breaks, I break back. But she kept hitting the big shots."

Shriver did break back for 5-3 and served for the match. Graf thereupon played her best game of the match, slapping a forehand passing shot and a forehand she caught in the air -- her only volley of the match -- then running down a drop shot to hit a cross-court winner for the game.

Both women held and, for the first time in Open history among the women, they went to a third tie breaker. Graf quickly took a 3-1 lead, hitting a forehand return down the line that a lunging, grunting Shriver could barely touch. But Shriver won the next three points to go up, 4-3.

"Again, I was so close," Shriver said, her voice trailing off.

She wasn't close for long. Graf hit a low backhand that Shriver pushed wide for 4-all. Graf hit a backhand down the line that Shriver opted to volley -- it might have gone wide -- but netted. It was 5-4. Graf got in a first serve, Shriver was wide with the return.

Match point. One more time, Shriver tried to follow a backhand in, but she tried a little too hard and the ball floated deep. Shriver stopped in her tracks, shocked. So did Graf. Finally, both players understood the marathon was over, as did the entranced audience that let both women know how it felt as the two shook hands.

"I am as happy to win this match as I have ever been," Graf said. "I haven't even thought about playing Martina."

Shriver had. "If I had hung in like this last year in the quarterfinals (against Wendy Turnbull), I'd have played the semifinals," she said. "At least I fought right to the end. Still, I wish it had been different."

As Shriver left the court, she embraced longtime coach Don Candy and cried again. Several yards away, Graf found her father and she, too, let the tears go. It was only proper. Both women had earned the right to let their emotions show.

McEnroe was his old self again -- in more ways than one -- in beating Nystrom.

McEnroe, the No. 1 men's seed, hit a barrage of winners in his straight-set victory, but he also reverted to his tempestuous self, calling the chair umpire "boneheaded," accusing the tournament referee of drinking on the job and demanding that the TV technician who wields the on-court microphone be removed.

McEnroe's troubles began when he was leading, 2-0, in the third set and had a break point. He hit a forehand that was close to the base line. It was first called good and McEnroe walked to his chair, thinking he had taken the game. But the line judge reversed herself and umpire Steve Winyard ordered the point replayed.

"Why do you wait so long to tell me?" McEnroe said, then lost the point and the game. Nystrom suddenly picked up -- he had lost 13 straight games -- and won five straight games.

Trailing, 3-2, and frustrated, McEnroe yelled at Winyard, "You see what one boneheaded call can do?" For that, he was the recipient of a warning.

Trailing, 5-2, McEnroe asked to talk to tournament referee Bob Howe and Grand Prix official Ken Johnson. They came to the court. McEnroe asked them to remove the CBS technician. "They've put that same guy on all my matches for years," McEnroe said. "Whether I'm right or wrong about him pointing it (the microphone) more at me, I don't see why they can't have someone else hold the mike."

Howe didn't see it that way. Furious, McEnroe said, "What do you know, anyway? You're sitting in the back drinking and not doing your job."

His venom spent, McEnroe, as he put it, "went back to my business" and won the next five games, saving one set point, to take the set and the match.