Acupuncture couldn't help. One doctor told him nothing would help and advised him to find another job. Not even nature, the doctor said, could help the torn tendon in Kim Warwick's shoulder.

"If I was 20, it probably would have mended," he said. "At 30, the blood supply just isn't good enough."

But Warwick wasn't ready to abandon tennis, as Yannick Noah learned today. Warwick has won only four matches since reinjuring his shoulder in February, two of them against seeded players at the U.S. Open. In the first round, he defeated No. 7 seed Jose-Luis Clerc. Today, in the fourth round, he beat ninth-seeded Noah, 5-7, 6-3, 7-5, 6-4.

Warwick, a man of many comebacks, came back three times from 0-40 to hold his serve, the last time in the last game, serving for the match. An ace gave him match point. A service winner gave him the match.

"I was hoping ace," he said. "I was thinking first serve in."

Asked this afternoon how he would rate tonight's Ivan Lendl-Mats Wilander rematch (Wilander beat Lendl on his way to winning the French Open), Warwick said, "They're exactly the same. It will probably be a boring match, I'd say."

He was so right. Lendl, who has never done what Wilander did at age 17 (win a Grand Slam event), beat Wilander, 6-2, 6-2, 6-2.

Lendl took a 2-0 lead in each set and never lost his serve. His ground strokes were as penetrating as Wilander's were errant (Wilander made 37 unforced errors). His passing shots were useless against Lendl's back court game and desire for retribution. "I got a lot of garbage from everybody for losing to someone no one ever heard of," Lendl said.

Warwick wasn't the only one advancing to the quarterfinals who wasn't supposed to. Gretchen Rush, a freshman at Trinity University who is playing as a wild card, had beaten 11th-seeded Mima Jausovec in the second round; today, she defeated sixth-seeded Wendy Turnbull, 6-3, 4-6, 6-2. Then she went out and won her first-round match in the junior tournament, 6-1, 6-0.

The other results were far more predictable: Martina Navratilova, No. l, defeated Andrea Leand, 6-1, 6-2; Tracy Austin, No. 2, who has never lost a set to Virginia Ruzici, beat her, 6-4, 6-2; Andrea Jaeger, No. 4, beat Kathy Rinaldi, 6-1, 6-1; Hana Mandlikova, No. 5, beat Vicki Nelson, 6-4, 6-2, Pam Shriver, No. 7, beat Rosalyn Fairbank, 6-4, 6-4.

Gene Mayer, No. 6, beat another oldie but goodie, 35-year-old Bob Lutz, 6-4, 6-2, 6-1. His quarterfinal opponent, top-seeded John McEnroe, looked increasingly sharp, increasingly like himself, beating Matt Doyle, 6-3, 6-4, 6-4.

Later, however, McEnroe and Peter Fleming, the defending doubles champions and No. 1 men's team, lost in a major upset to No. 5 Victor Amaya and Hank Pfister, 2-6, 7-6 (9-7), 6-3, 6-1.

McEnroe thought he served and volleyed well in his singles match, but true to his self-critical self, was unhappy with his lack of concentration in spots.

"It's going to have to be better from this point on," he said.

Rodney Harmon of Washington, who is unseeded, plays No. 8 Eliot Teltscher in another quarterfinal match Tuesday.

The shoulder injuries have left Warwick a changed man. He doesn't hit the ball as hard, but his touch is fine although he is playing on borrowed time, with a repossessed shoulder.

He had 11 match points against Adriano Panatta in the Italian Open in 1976 and lost. He had three match points against John Alexander at Wimbledon this year and lost. He was also known for ranting and raving.

"It cost me a lot of matches," Warwick said. "Now I've got a family to support. They're out there spending money."

So he has to win, and today he played that way. Noah won the first set, breaking at 5-5, and then holding serve. From then on, he was barely holding on. In the fifth game of the second set, Warwick fell behind, 0-40, and won the next five points. Noah won the first three games of the third set.

"I had a game point to go up, 4-1," Noah said. "But I lost the point and the break. That was the most important moment."

So it was 3-2. Warwick served and fell behind, 0-40, again. A lovely forehand drop volley brought them to deuce the first time. After Noah took the advantage (his third break point), Warwick served an ace and they went to deuce again. Warwick fought off another break point, winning the game with a wondrous stretching forehand cross-court volley, and went on to win the set.

The fourth-set denouement was a thing of beauty. Warwick broke twice, then Noah broke at 4-2. Each held serve, then Warwick came back from 0-40 to win the final game.