Roscoe Tanner looked across the net and thought he saw Bjorn Borg. He saw a man whose topspin passing shots reminded him of the ones that finally wore him down in the fifth set of the 1979 Wimbledon final against Borg. He saw a man named Mats Wilander. "I played him exactly the same way," Tanner said. "A couple of things he does different from Bjorn, but a lot of the things are identical."

This time, the Swede didn't win. Tanner, who has played only four tournaments this year, beat Wilander, the No. 5 seed, 6-7 (6-8), 7-5, 6-3, 6-4, in the third round at Wimbledon.

Last fall, Tanner came ever so close to retiring from tennis at the tender age of 30. He had a new baby and an oil drilling business to attend to. His ranking had fallen from fifth in 1979 to 43rd. Borg was on the verge of retiring. The challenges didn't seem so great anymore. He had become more interested in protecting what he had become than exploring what he could be.

Then, he decided, "Let's forget where you were, let's try and go out and be better."

Today, the better Tanner (but the one ranked only 140th in the world) won, serving 19 aces although double-faulting eight times, teaching Wilander a grass court lesson he won't soon forget.

It was a wacky, wonderful day at Wimbledon.

Jo Durie, who is England's new hope (and the 13th seed) lost to Eva Pfaff, 7-6 (7-3), 7-5. Virginia Wade, who at 37 is England's old hope (and last Wimbledon champion) won, 3-6, 7-6 (7-3), 6-2, after being down 5-1 in the second. "I am playing for fun," Wade said. "But it's more fun if you win."

Martina Navratilova struggled more with her wraparound skirt than she did with Mima Jausovec, winning, 6-2, 6-1. Navratilova's skirt unraveled a bit on the first point of the match; Jausovec unraveled soon after under pressure from Navratilova's attacking game in a match that took only 40 minutes.

In a women's upset, ninth-seeded Sylvia Hanika lost to Jenny Mundel, 2-6, 6-4, 6-3.

Ivan Lendl, the No. 3 seed, was perturbed with himself for not closing out his match with Jakob Hlasek in the third set, when he had three match points. He finally won, 6-1, 6-2, 6-7 (5-7), 6-4, and admitted, despite his allergies, how important it is to win on this pastoral surface.

When someone asked whether winning the Grand Slam is a goal for him, he said, "I'm pretty far from that. I'd like to win one Grand Slam event first. I didn't win the ones I'd like to. I give you all the other titles, if you give me one Wimbledon and one U.S. Open."

No. 2 seed (behind Jimmy Connors) John McEnroe had a placid, easy time, against Brad Gilbert, winning, 6-2, 6-2, 6-2. Only in the first set did McEnroe even question a call. In the eighth game, after one of his shots was called wide, he asked umpire Bob Jenkins, "You sure of that call?"

The 14th seed, Bill Scanlon, beat Tim Gullikson, 6-4, 6-4, 6-3.

Johan Kriek, the 11th seed, was upset by Ricardo Acuna, 6-3, 7-6 (7-4), 6-1, and upset with the food. "Wimbledon has probably got the worst food of any Grand Prix event," he said.

Kriek provided the day's comic relief. Tanner and Wilander provided the best 2 hours and 20 minutes of tennis. Last spring, during an exhibition tour with Borg, Tanner developed a bone chip in his left elbow. He kept playing anyway and went to a tournament in Richmond where he was scheduled to play McEnroe, who was hurt, too. Tanner figured he would wait and see who defaulted first. Neither did. Tanner won.

His arm got worse and soon he couldn't raise it high enough to comb his hair. The doctors said rest was the only prescription. If he had undergone surgery, his career might have been over before he recovered.

He took about two months off to work with a pro, Jerry Hatchett, at a club in Santa Barbara, Calif., where he lives. They worked on improving his volleys, learning to move closer to the net, angling volleys more sharply to elude base liners like Wilander. For once, he couldn't serve (he has been clocked at 135 mph, but he says he's slowed down) so he worked on his returns and passing shots instead.

It was all in evidence today. Over and over, he returned Wilander's serve for clear-cut winners. His volleys angled sharply. The big serve was always there when he needed it. His game was always suited to grass, especially to Wimbledon, where he has been a a runner-up once and a semifinalist four times. He forced Wilander out of his game. The more Wilander served and volleyed, the more uncomfortable he looked.

Before the match, Tanner studied a film of Wilander's loss to Yannick Noah in the final of the French Open. Although that match was played on clay, he could detect patterns that reminded him of Borg. "Basically, he doesn't miss with his backhand down the line," he said. "You might as well cover and volley. Borg didn't miss it either."

"A lot of the shots I tried were exactly the same ones I would have tried against Borg. When I was at the net, looking for him to hit a passing shot one way or another, I looked for the shot Borg used to hit."

Tanner served at 4-2 and up a break in the third set. Wilander passed him with that backhand down the line for a break. But Tanner reciprocated, breaking back with a forehand cross court winner on the return of serve, and served out the set.

When Wilander took a 2-0 lead in the fourth set, it seemed possible that Tanner might wilt under the pressure of Wilander's passing shots. But Wilander double-faulted to give Tanner a break point and Tanner made the most of it. He wound up and sent a vicious forehand at Wilander, who was standing, vulnerable, at the net. Wilander lunged for the backhand volley and netted it, making it 2-1. Tanner then held to tie at 2.

Wilander, not quitting, broke again shortly thereafter to make it 4-3. He served to even the match and, strangely, decided to serve and volley.

He fell behind, 0-30, as Tanner passed him from the base line, their roles seemingly reversed. A forehand return winner gave Tanner the only break point he needed. A backhand cross court gave him a chance to serve for the match. He served and won. An ace gave him match point. One of those new crisp volleys, off one of those backhand cross court passes he anticipated, finished it. He left the court with his fists pumped high in the air. Now, he says, he may play another year or two. Learning to win a new way has made it interesting again, fun again.

"I had gotten very worried about protecting what I had already done," he said. "What I've already done isn't going away. It's in the record books. Now, I'm looking at doing something new."