John McEnroe insists he doesn't have to play volatile tennis to play winning tennis. Today, he contained himself and the furies that dwell within him and was contained by Bill Scanlon, who beat McEnroe at his own game and on his own turf, 7-6 (7-2), 7-6 (7-2), 4-6, 6-3.

On Labor Day, everything worked for Scanlon. Nothing worked for McEnroe. Scanlon, the 16th seed, played like the No. 1 seed. McEnroe, the No. 1 seed, played like the 16th. Scanlon served better, returned better, behaved better and anticipated better. No matter where the ball went, he seemed to get there first. When it was over, Scanlon let out a long suppressed cry of joy, a "Yeah!" heard round the world.

From the beginning of the 3 hour 44 minute match, McEnroe's concentration wandered, along with his passing shots. His volleys caught the net as he caught his temper. Finally, serving at 2-2 in the fourth set, he was distracted by the noise of the crowd as it admired one of Scanlon's shots and approached the umpire's chair. Ken Slye of Alexandria, Va., asked the crowd to contain itself. "Please don't come out with oohs and ahhs during play," Slye said.

He was inundated with boos. The New York kid had alienated the New York crowd. McEnroe went to his chair and sat down. He returned to the game and missed two forehand volleys to give Scanlon break point. A forehand net cord return at McEnroe's feet gave Scanlon the first break of the set. He broke again in the last game to win it.

Scanlon lost to McEnroe in the fourth round of Wimbledon, 7-5, 7-6, 7-6, the last time they played, and had four match points against him the time before that. He said today he was more determined than ever to show he could win a match like this, to outplay McEnroe on the big points, which both agreed he did.

"You key on it by remembering what you're supposed to do, make sure you step into the ball, get your momentum going," Scanlon said. "A lot of times, when it's a big point, you have a tendency to stand back and play reaction tennis. Today, I didn't do that at all."

Ranked 17th, he began 1983 71st, with a reputation of unfulfilled potential. "If you are going to have a big win, what more could it be than to beat the No. 1 player in New York at the U.S. Open?" he said. "The crowd (20,701) was unbelievable."

McEnroe thought so, too, but said, "I could blame the crowd, the airplanes, the umpires, but in the final analysis, I didn't play good enough . . . I have no one to blame but myself."

Scanlon's vindication over his Wimbledon loss to McEnroe overshadowed everything else, including Chris Evert Lloyd's vindication over Kathy Jordan for her Wimbledon loss. It was a happy day for Evert, who won, 6-3, 7-6 (8-6), but a sad one for her husband John Lloyd, who lost to Mark Dickson, 6-7 (8-10), 7-6 (9-7), 6-0, 7-6 (7-3).

All the other top seeds in action this afternoon won, which was a relief because the day could only bear so much drama. In night matches, Martina Navratilova, the top women's seed, defeated Pilar Vasquez, 6-0, 6-1, and Jimmy Connors, the No. 3 men's seed, beat Heinz Gunthardt, 7-5, 6-4, 6-1.

McEnroe had not lost this early in a Grand Slam event since Paul McNamee beat him in the third round of the French Open in 1980. He had not lost this early in the U.S Open since 1977, when Manuel Orantes beat him in the fourth round.

Early on, it was clear that it was not McEnroe's day. With Scanlon serving at 5-6 in the first set, McEnroe objected to a call on a forehand volley that gave Scanlon 30-30. Scanlon held and they went to the tie breaker. McEnroe stood at the base line, refusing to serve, bouncing the balls vehemently with his right hand until Slye cited him for a code violation of time delay. Slye was cheered and McEnroe booed as he approached the chair for some conversation.

McEnroe was fined $1,850 during his first-round match with Trey Waltke for ball abuse, umpire abuse and spectator abuse. His total fines for the year are $7,300, which is $200 short of a mandatory 21-day suspension. McEnroe made it clear that he would have to behave if he was going to be able to play Davis Cup this fall in Ireland, which he very much wants to do. "I couldn't afford to say anything obscene," he said.

He let two more calls on first serves in the tie breaker disturb him and fell behind, 2-5. A forehand pass gave Scanlon set point. McEnroe stopped dead in his tracks when his first serve was called long, and later wondered why the linesman had called the serve long when the machine used to make those determinations had not sounded. He attacked behind his second serve and missed an easy forehand volley to give Scanlon the first set.

He struggled to stay in the second. Scanlon was sharp. McEnroe seemed to lack focus and precision. He made 14 unforced errors to Scanlon's four. His first-serve percentage was 51.4 to Scanlon's 57.1.

They went to a second tie breaker. But McEnroe, who said he never could get untracked, was not in this one, either. Scanlon got a minibreak, which he never lost, at 1-all, when McEnroe fended off three of his best passing shots but not a fourth. Scanlon won the next five points.

The match was 2 hours 58 minutes old when McEnroe won his first set, but it didn't come easily. Scanlon had two break points in the ninth game that would have allowed him to serve for the match. But McEnroe held firm, then broke as Scanlon played one of his few loose games of the match.

The game and the tactics that helped McEnroe win Wimbledon, that helped him win the Open in 1979-1981, failed him. With Scanlon serving at 0-1 in the fourth set, McEnroe swooped in on a short ball, wound up and aimed a backhand cross court at Scanlon's navel.

It got him a point but it made none. Scanlon, who had earlier wagged a finger at McEnroe when he aimed another shot at Scanlon's head, started to hit one back at him and refrained. "We're not best of friends," McEnroe said.

Scanlon soon was tested again. Serving at 1-2, he fell behind, 0-40, giving McEnroe his best chance to get into a match he had never been in. He saved the first when a forehand lob went long, the second with a well-timed backhand volley off McEnroe's backhand approach and the third with a big serve to McEnroe's forehand that gave him an easy volley.

He broke McEnroe in the next game, amid the oohs and ahs that disturbed McEnroe so.

"I played a disappointing match," McEnroe said. "It's too bad it had to happen here, but the people seemed to be happy about it."

Did he really think they were happy to see him lose? "Absolutely," he said.

And that may have been the most disappointing thing of all.