NEW YORK, SEPT. 9 -- John McEnroe had Ivan Lendl right where he wanted him tonight. The two dominant male tennis players of the 1980s were on the stadium court at the National Tennis Center, playing before a packed house that seemed poised to will McEnroe to victory if he had even half a chance.

But Lendl wanted no part of any late night dramatics or theatrics. He played an almost flawless match from start to finish, thrashing McEnroe, 6-3, 6-3, 6-4, to reach the U.S. Open semifinals.

Lendl's opponent Saturday will be another familiar face, one James Scott Connors. This afternoon, Connors proved his grit for the umpteenth time, coming from behind to beat Brad Gilbert, 4-6, 6-3, 6-4, 6-0. Gilbert beat Boris Becker on Monday, but today, after playing a superb first set, he didn't respond when Connors figured him out.

"I think he got tired after a while," Connors said. "He came out playing really well but once I got the break in the third set, I felt like he was tiring. I just had to stay on top of him after that."

Connors got the key break of the match to go up 4-3 when Gilbert double faulted on the fourth break point of the game. Gilbert had three break points of his own when Connors served for the set at 5-4, but Connors saved them all, and won the set when he nailed a backhand that landed right on the side line and the base line. Gilbert, chasing the ball, stopped when it landed, apparently believing the ball would go out.

When the ball was called good, Gilbert threw his racket down and argued -- to no avail. Having lost the argument, he quickly lost the last set, as Connors reached the Open semifinals for the 12th time in 13 years.

"Getting to the semis is nice, but it isn't satisfying," Connors said. "I want to get over the semis hump and do more."

That will be a formidable task, to say the least. Lendl has beaten Connors the last 13 times they have met and tonight, against his old antagonist McEnroe, he was brilliant. "I didn't want fireworks," he said when it was over. "I just wanted to win."

There were no fireworks, no explosions from McEnroe; no suspense at all, in fact. Lendl was just too good. "He played a great match," McEnroe said. "It wasn't like I played bad or anything, he was just doing a lot of very good things. He's dedicated his whole life to the game and right now it's paying off for him. I have other things in my life right now. But I still feel like I'm going in the right direction."

Briefly it looked as if McEnroe would make this match live up to its billing. He came out firing and with Lendl serving at 1-2, deuce, it looked like a long, intense night was ahead. Lendl had other ideas. He saved that game with the first in a series of topspin lobs that must have made McEnroe dizzy. Then, after McEnroe held to lead, 3-2, Lendl went on a seven-game run.

After Lendl held at love -- the first of four straight service games in which he didn't yield a point -- McEnroe broke himself with three double faults in the next game. That break led to McEnroe's only real confrontation with umpire Gerry Armstrong tonight. Because the record nighttime crowd was on milling about on every changeover, there was no way for the players to begin play after the 90 seconds was up. McEnroe decided to wait the crowd out from his seat. Armstrong didn't like that and they argued until the crowd settled.

Lendl hardly seemed perturbed. Nothing seemed to bother him tonight. He quickly ran out the set, breaking McEnroe again with a forehand return that had such force it knocked the racket out of McEnroe's hand. Lendl quickly broke in the second game of the second set with another gorgeous topspin lob and raced through that set with equal ease.

"I just couldn't find anything to do with him," McEnroe said. "His adrenaline just seemed to keep him going all night long."

The crowd certainly tried to help McEnroe. Anytime he held serve, the cheers were raucous. On those rare occasions when he won points on Lendl's serve -- Lendl won 21 straight points at one point and never faced break points -- they urged him on. But it didn't matter.

"If he had broken me early in the first set, it might have been a different match," Lendl said. "But he just played a lousy game at 3-all and I won seven games in a row. Basically that got me up two sets to love and I went from there."

The only break Lendl needed in the third set came in the third game on two prototype forehands, one a passing shot, the other a return. McEnroe took a deep breath, put his head down and didn't even look as the last winner whistled past him. He knew that the shot he had wanted at Lendl in this tournament had come and gone.

Lendl served out the match from there, reaching the Open semifinals for the sixth straight year and winning his 19th straight Open singles match.

He seemed more relieved than happy after the match.

"Anytime I play McEnroe I expect a tough match because we've played so many times," he said.

"Right now he isn't playing as well as he did in '84 but he's playing better than he did last year. I know if I go out and play good solid tennis and he doesn't play great, I should win. But I always worry that he might play great."

McEnroe isn't at that stage yet. He has come a long way back, mentally and physically, but tonight proved definitively that he still has a long way to go before he can seriously challenge Lendl. Of course it may be that right now no one can seriously challenge Lendl.

The man most people think has the best chance to beat Lendl, Stefan Edberg, reached the quarterfinals today, playing a day behind because of Tuesday's rain.

Edberg beat Jonas B. Svensson in straight sets and now plays Ramesh Krishnan, another straight set winner today over Andrei Chesnokov in the quarterfinals.

Krishnan, the only nonseed still playing, has not lost a set in four matches and last year gave Edberg fits before losing to him 6-4 in the fifth set in a third round match.

The other quarterfinal will be a rematch of a year ago: Mats Wilander against Miloslav Mecir. Wilander, who beat Ken Flach today, has also not dropped a set. Mecir, a finalist last year, needed four sets to beat Mark Woodforde today, 6-4, 3-6, 6-2, 6-2.

But the best match of the day was Connors-Gilbert. At 35, Connors is too old to wear down an opponent in a three-hour match. But he doesn't know that. It took him a set to figure Gilbert out as the 26-year-old Californian junk-balled him, not giving him the pace he loves to feed off and extending the rallies to make Connors run on his sore right foot.

But Connors is rarely outsmarted. Overpowered perhaps, but not outsmarted. He began to pick his spots to come in, became more patient and gradually took command of the match. In the end, his mind and body were too strong for Gilbert.

He ended the match with a screaming forehand winner and earned one more standing ovation as he walked off with a hard-earned victory.