Ivan Lendl's serve gave Jimmy Connors no time to react, much less think. Connors' best return of the day came in reply to a question after the 62-minute match was over. "Boring wasn't it," he said.

Not for Lendl, the defending Masters champion, who won, 6-3, 6-1, not quite avenging his loss to Connors in the final of the 1982 U.S. Open. "I'd rather give him this and take the Open," said Lendl.

Lendl's serve was a laser. He had eight aces and seven service winners. Connors, who has the best returns in the sport, went for all them. But that didn't mean much. "When he's whacking it, he's whacking it," Connors said.

John McEnroe, who has historically fared much worse against Lendl than Connors (Lendl leads McEnroe, 6-3), will get another whack at him in the final Sunday afternoon. McEnroe, the fourth seed, beat Guillermo Vilas, 6-3, 6-3.

Connors was the favorite of the 18,309 people who filled Madison Square Garden for the first time this week. They booed Lendl's few mistakes and exhorted Connors relentlessly. It wasn't enough.

"I was happy," said Lendl, who has beaten Connors only once before (6-1, 6-1 last year in Cincinnati). "I was playing so well. I didn't feel there was much he could do. I was hitting the ball deep and hard. With that kind of serve, it is difficult to do anything."

Only Friday, Lendl was unhappy with his serve. Today, he began tossing it higher. What a difference a toss makes. Though there was only one break in the first set, Lendl was always in command. Connors, who did not return as well as usual, had only one break point all day, in the second set.

"As far as being awesome, you're awesome when you blow somebody out," Connors said. "He kept a lot of balls out of reach when he was serving. Once the ball's in play, I was in there."

He was there, but perhaps a bit daunted. Lendl's scintillating forehand, which abandoned him during the Open and went spraying every which way, was under control. This time, he pulled Connors every which way. A forehand cross court that skidded under Connors' racket gave Lendl a break point in the fifth game. A backhand passing shot down the line gave him the break.

In the second set, the differences became more pronounced. Lendl hit out. Connors hit awry. He made eight forehand errors. Later, he said he needed more matches, that he didn't feel alert.

So it seemed, as he fell behind, 4-0, in the second set. Finally, in the fifth game, he got a break point when Lendl's backhand cross-court shot (his only backhand error of the day) went wide. Connors broke with a forehand cross court that skimmed across the net low at Lendl's feet, the way so many of his shots did last September at the Open, and Lendl netted a forehand in return.

But Lendl, who is so often criticized for not winning at the big tournaments and for his steely demeanor, was as good as his mettle. He broke right back, and served out the last game at love.

"Anything I tried was just about to go in," he said. "When you play a guy who hits the ball as hard as he can, hits the lines or the corners all the time and doesn't miss anything . . . "

He didn't bother to finish the sentence.

McEnroe and Vilas know each other's games so well, they can practically finish each other's sentences. They have played 12 times (each winning six), not including the recent exhibition tour they just completed. So each figured he had to try something different in the semifinal. Vilas, the second seed, decided he would attack more.

McEnroe foresaw the danger of being lulled into staying back, so he wanted to attack more, too. But Vilas presented him with an unexpected number of opportunities to go for passing shots. He passed better than Vilas volleyed. He served better than he did earlier in the week--nine service winners and one ace--and he won.

"He knew I would come in and attack," McEnroe said. "He tried to do the same. But he rushed a little."

McEnroe broke in the first game of the match, and barely looked back, except over his shoulder at the umpire, Charlie Beck, whose judgment he occasionally questioned. The argument ensued at break point for McEnroe in the fourth game. Vilas put an end to a lovely point with a backhand winner down the line. McEnroe, who has been diligently working to improve his behavior, was convinced it was long and let everyone know it. "I'm hyped out when I come out on the court," he said. "Maybe I should go in the bathroom and scream before I go out on the court. It's the one thing I have to worry about. I was going to go up two breaks. I wanted that."

He got it anyway, when Vilas rushed one of his shots and netted a backhand approach to give McEnroe another break point. Vilas, backpedaling, reaching for a lob, rushed again, hitting it before it bounced and netting it to give McEnroe the break.

Vilas saved a break point in the sixth game of the second set, and another in the eighth. McEnroe attacked a second serve, and Vilas placed a wonderful backhand cross-court winner out of his reach. McEnroe, angry with himself, cried, "You're a horse's . . . " In keeping with his new image, he didn't finish the thought.

Instead, he went for a winner on the next point, a forehand cross-court winner that gave him another break point. A sharp backhand cross court that contrasted with the soft, almost gentle pace of most of the exchanges, gave McEnroe the break and the chance to redeem himself in his own eyes against Lendl. Asked before Connors lost, who he would rather play, McEnroe said, "If I knew I was going to win, I would rather play Lendl."