In a match that added another extraordinary chapter to the rivalry between the world's two best tennis players, and will be remembered most vividly for Bjorn Borg losing his temper and being penalized two points in the second-tie breaker, Borg defeated John McEnroe, 6-4, 6-7, 7-6, early this morning, eliminating the U.S. Open Champion from the $400,000 Volvo Grand Prix Masters tournament.

This bizarre and gripping contest alternately delighted and infuriated a sellout crowd of 19,103 spectators at Madison Square Gardern, but it is destined to go down in tennis lore as the night Borg briefly lost his legendary cool and argued for four minutes with British umpire Mike Lugg, who docked him two crucial points for delay of game.

There were three other matches on this second day of round-robin play in the Masters. Jimmy Connors, Ivan Lendl, and Gene Mayer also increased their records to 2-0, and qualified for Saturday's semi-finals along with Borg. Guillermo Vilas, Harold Solomon and jose-Luis Clerc, like McEnroe, lost for the second day in a row and were also eliminated.

But everything else that happened paled in comparison with the latest dramatic masterpiece in the Borg-McEnroe rivalry, which built in tension for 2 hours 43 minutes and ended at 20 minutes past midnight with Borg again proving his strength of character.

Borg had narrowly but surely maintained the upper hand for the better part of two sets, and served for the match at 6-5 in the second. But then McEnroe -- displaying the same combativeness that enabled him to stretch Borg to the limit in last year's majestic Wimbledon final, and beat him in another five-set epic in the U.S. Open final two months later -- hung in grittily, broke back, and forced the tie breaker that turned into something from Never Never Land.

Never does Borg, the most solid and unflappable of champions, lose his temper. But he did Thursday night.

When the forehand passing shot that he hit at 3-3 in the tie breaker was called out by the umpire Lugg, overruling a linesman who insisted that it was good, Borg became furious. He didn't rant and rave, but neither did he give in. He was sure the umpire was wrong and voiced his objections, firmly and at length.

Standing beneath the umpire's high chair, motioning with the racket in his right hand to the spot where he felt he had been wronged, Borg startled everyone -- spectators, officials, and McEnroe alike -- by refusing to accept the call and play on. After a full two minutes of discussion, Lugg looked straight ahead with an implacable expression and issued this warning: "Reporting Mr. Borg. Time delay."

Standing his ground with jaw set, as immovable as a statue, Borg kept glaring at Lugg and said nothing until the umpire followed his warning with a point penalty, making the score 5-3 for McEnroe. Thirty seconds later, he assessed another penalty, making it 6-3, set point for McEnroe.

Jeers and catcalls filled the vast, tension-charged arena. McEnroe, who had angrily argued several line calls earlier, waited -- confused and embarrassed -- in front of the backdrop. "I didn't know what to do. I couldn't believe that was happening," he would say later. "It was incredible that something like this could happen to Borg. I didn't know whether I should tank the match or try or what. I almost wanted to ask the umpire to play it from 4-3. I didn't want to take the penalty points."

Borg, who later said he was "100 percent sure the ball was good" and that he was very upset with the umpire, finally decided to play, but knocked a backhand wide to lose the suddenly farcical tie breaker, 7-3.

Into the decisive third set they went. The crowd had no idea what to expect. People had never seen anything like this from Borg before. "I think he's going to blow sky-high," predicted one astonished aficionado.

She was wrong. Borg and McEnroe, whose grand battles last year elevated their rivalry to a lofty plane that has captivated the public imagination, both played magnificently despite a few more acrimonious disputes. In the end, Borg protested four times and played like fury.

The remarkable 24-year-old Swede played more aggressively in the final set than he did earlier in the match, serving mightily and coming to the net. McEnroe, forgetting completely about the hamstring muscle he had pulled in losing to Mayer the previous night and had heavily taped, matched him stroke for stroke, coming in behind clever chips and slices and volleying like a demon.

Neither player had a break point in the set, and the match wound its way inexorably into another best-of-12-point tie breaker. This time, Borg was all business.

At 1-1, Borg won perhaps the most important point of the whole affair. Borg rifled a great return of a second serve, McEnroe somehow intercepted it with a lunging forehand drop volley that looked like a winner, but Borg swiftly got to the ball and looped a topspin forehand passing shot down the line into the corner. That made it 2-1, and Borg was never behind thereafter.