It was not a classic, not a masterpiece along the lines of their Wimbledon final two years ago or their quarterfinals here the last two years. But today Bjorn Borg and Roscoe Tanner added a new dimension to one of tennis' fascinating rivalries, a match in which Tanner, although stripped of his most dangerous weapon, made Borg struggle to the finish.

The Swede came away the victor in their annual U.S. Open quarterfinal, 7-6, 6-3, 6-7, 7-6, with a 9-7 fourth-set tie breaker after Tanner lost a set point.

In Friday's women's semifinals, Chris Evert Lloyd meets Martina Navratilova and Tracy Austin plays Barbara Potter.

The fascination today was the sight of Tanner, with his shaky first serve and inability to break Borg for almost four sets, coming within one point of sending the match to a fifth set.

"Maybe Roscoe didn't serve his best today," Borg said. "But a lot of times when I had him love-30 he came up with something to hold his serve. It was a tough match for me even though I thought I played well."

By contrast, Borg's semifinal opponent, Jimmy Connors, absolutely strolled through his quarterfinal match, a 6-3, 6-1, 6-2 embarrassment of Eliot Teltscher, a match that gave the night crowd none of the thrills provided by Borg and Tanner.

Teltscher, 22, is one of the game's rapidly improving players. But he plays almost the same style as Connors, slugging away from the baseline time and again. Against Connors though, Teltscher is a clone without the first-line materials. Connors hits a little harder, is a little more consistent and a little more sound when he does come to net.

The results are predictable: Connors 7, Teltscher 0 in career meetings. Tonight was the same as in the past. Connors, reaching the semifinals here for the eighth straight year, broke Teltscher in the first game of the match and rolled on from there, crushing his ground strokes with authority until the end.

The final point of the match was a microcosm: a long rally, Connors finding a ball to come in on, hitting an angled volley that Teltscher just got to but could not return.

Connors' only problem all evening was the $400 fine he received for making an obscene gesture -- directed at himself.

The afternoon match had the variety in pace and style the evening match lacked.

Tanner without his first serve is like Nolan Ryan without his fast ball. Today, he got just 49 percent of them into play as the match became one of sound -- the crack of Tanner's first serves hitting the net tape -- as well as sight. But fortunately for Tanner, his second serve, or his curve, was keeping Borg off stride and Tanner in the match.

"I didn't think I served poorly for me," Tanner said. "I thought the key to the match was my volleying. I just didn't play my first volleys well. He hits the ball kind of high, like a knuckle ball and it gets into the wind and is hard to handle. I had trouble with it all day."

Indeed, for a long time this match was not nearly as close as it appeared. That the first and third sets went to tie breakers was more a result of Tanner's grit than anything he did with his racket.

In the first three sets, Borg was dominant on serve and Tanner struggled in almost every game.

The second set was the quickest and least exciting of the match. Borg broke Tanner in the second game of the set with four brilliant winners, the last a cross-court winner.

From there, he methodically served out the set, Tanner never reaching deuce on his serve. It looked like a romp for Borg.

Even with his serve still failing him, Tanner began picking up his game in the third set and the two moved into yet another tie breaker. He even had two break points that Borg survived with an ace that might have been deep and a service winner that looked deep. Tanner argued vigorously on the second, but had little luck.

This time, Tanner played his best tennis of the sunny afternoon, one that brought a record crowd of 18,846 to the National Tennis Center.

With Borg serving at 4-5, Tanner followed his return in and this time hit a forehand volley with authority, punching it past the lunging Borg to reach set point. Again Borg served and this time he came in with a forehand volley of his own.

But Tanner ran it down in the corner and swept a forehand past Borg to win the set. Tanner punched the air with delight as the audience, rooting for a close match, screamed.

"It was difficult to hurt him with anything early," Tanner said. "But as the match went on I felt better, I started hitting the ball a little better as we went on. I don't think either one of us played as well as the last two years until maybe the last set."

The fourth set was the best of the match, serve and volley finally giving way to some genuine rallies and superb points. Borg broke Tanner to go ahead 3-1 when Tanner's Achilles' heel, the backhand volley, burned him twice. When Borg held serve at 15 to go up, 4-1, the end seemed imminent.

"I thought then I was in good shape," Borg said. "He hadn't broken my serve the whole match and I was feeling strong and confident. But he played a very good game to break me back."

But Tanner broke back with Borg serving at 4-2, his first break in 21 service games.

They went on serve until 4-5 when Tanner fought off two match points at 15-40 with a gorgeous overhead and one of his 12 aces. Two games later, it was tie breaker time again.

This time Tanner jumped ahead with a backhand pass a la Borg and two good first serves for a 3-0 lead. Borg rallied. He hit two winners and was helped by a Tanner double fault and a Tanner backhand into the net to reach 4-all.

By now, the crowd was into the match, yelling on every point, caught up in the tension that had taken over the court. A big Tanner serve put him at 6-5, set point. But he netted a backhand and a Borg service winner made it match point.

After Tanner scored with his service he chipped a volley wide and Borg had a fourth match point. This time he sent a final backhand cross court and, after 2 hours 50 minutes, he smiled for the first time.