Billie Jean King, who loves Wimbledon so, once vowed that when she retired she would take Centre Court with her. Had she kept her promise and quit in 1975 after she won her sixth title, she might have eased Ivan Lendl's life considerably. He is allergic to the grass that gives her goose bumps, an allergy so profound that he could not play here last year and had trouble the three other times he tried, never getting past the third round.

But King, who reached her 14th Wimbledon semifinal today, did not retire and Lendl was forced to come to terms with Centre Court. Today he beat Roscoe Tanner, 7-5, 7-6 (7-3), 6-3, to reach his first Wimbledon semifinal.

"In the past, he wasn't very smart; he skipped all the other (grass tournaments) and just came here," said Tanner, who knows a bit about playing on grass. "His game can be good on this surface. He volleyed better than I expected. He's got a big serve, he's got very good returns.

"He decided he was a clay court player; he didn't believe he could play on it (grass). When you don't believe you can do something, most of the time you're going to find out you're right. Now he's forced to play on it. He wanted everyone to say he was No. 1 last year and no one was willing to take him seriously as long as he wouldn't play Wimbledon."

Now Lendl will play the winner of Wednesday's quarterfinal match between John McEnroe and Sandy Mayer. Chris Lewis, who beat Mel Purcell, 6-7 (6-8), 6-0, 6-4, 7-6 (7-2), will play the winner of the Kevin Curren-Tim Mayotte quarterfinal.

King, who beat Kathy Jordan, 7-5, 6-4, is playing as well as she can, not as well as she could. Thursday, she will play Andrea Jaeger, the third seed who is half her age. Jaeger took time out from baking custard-filled fruit cakes to cook Barbara Jordan with her passing shots, 6-4, 6-1. Martina Navratilova, the defending champion, dismissed South African Jennifer Mundel in 47 minutes, 6-3, 6-1. Navratilova was broken only once, in the third game, when she double-faulted twice.

Virginia Wade's lovely odyssey was ended by Yvonne Vermaak, 6-3, 2-6, 6-2, who now must face Navratilova. At 37, Wade is just playing for the fun of it. At 39, King says, "It does take some of the weight off once you say, 'I'm just playing for fun.' For me, playing is fun. Winning is fun."

So it was fun today. King was too good for Jordan, though not by much. It was a well-played and tightly played match, both women scrambling for gets, rushing the net. It was thrust and parry, each saving a break point in the first game she served. Jordan served at 5-5 and went ahead, 40-30. King applied pressure with sharp returns and sharper volleys. A forehand pass sent them to deuce for the first of four times.

Three times Jordan saved break points. On the 13th point of the game, King returned a funky little backhand cross court. Jordan reached it on the full run, but was passed by a lovely backhand. On the fourth break point, King's forehand return landed near the base line. Unwisely, Jordan elected to let it go. It was called good. Jordan hit a ball sky high, clearly not how she was feeling. King served for the set and promptly fell behind, 15-40. She saved four break points in the game, as Jordan struggled to will herself past a legend. On the fourth deuce of the game, King missed a first serve and, staying back, dropped a backhand drop volley across the net. Jordan's running forehand went wide down the line.

King had the advantage. She won it on a lovely point with a forehand smash that Jordan anticipated and reached. But again her forehand went wide. King had the first set. Jordan dropped her racket and said, "Damn." King had three break points in the first game of the second set and was irritated with herself for letting down and letting go.

"I have to pretend I lost the first set, pretend I'm down," she said. "I tend to play only as well as I have to. I don't know if I like the drama or what."

The drama continued until the third game, when King gained another break point, with yet another crisp backhand cross-court return. A forehand chip return broke Jordan's serve and a bit of her spirit.

Lendl is as stolid as King is emotive. Emotion? "It's in my volleys," he said. And in the forehand returns and the first serves that boomed past Tanner for 11 aces, to Tanner's 13.

Last year at this time Lendl was playing in the pro-am of the Westchester Open in New York. Though he was the 1978 Wimbledon junior champion, he lost in the first round in 1979, in the third round in 1980 and again in the first round in 1981. After losing in the fourth round of the French Open last year to Mats Wilander, he decided he was not mentally or physically prepared for Wimbledon. This year, he came to play and today it showed.

With Tanner serving at 5-5 in the first, Lendl broke with two forehand returns that forced Tanner into errors. Lendl served for the set. Tanner tested him and lost. Seven times they went to deuce. Twice, blistering backhand returns kept Tanner in the game. Three times, he had break points but could not capitalize.

"Seemed like 25 to me," Lendl said. He saved the first with an ace, another with a forehand approach winner and the last with a backhand volley winner. Lendl served to Tanner's backhand, a ball close into his body. Tanner thought the serve was long, returned it weakly into the net, then protested weakly to the umpire. Lendl served for the set for the fifth time. Tanner, seemingly disconcerted by the earlier call, feebly returned a second serve into the net. "That isn't what beat me," he said. "He beat me."

Tanner had his chances to break in the second set, three break points in the second game. Lendl saved two of them with aces. During that game, Lendl took a misstep (one of the only ones he made all day) and felt something crack in his right ankle. He called for the trainer and the umpire offered him 60 seconds to have his foot taped. He declined the offer. "He was limping around and then he ran like a gazelle," Tanner said. They went to the tie breaker without either breaking serve. Tanner played it poorly, double-faulting on the first point. A backhand long gave Lendl a 2-0 edge and a perfectly placed backhand cross court volley made it 3-0. Tanner, unraveling a bit, hit a half volley long and it was 4-0 before he got a point.

Later, Lendl was asked what he has learned from this Wimbledon. He said he hadn't thought about it. When King was asked the same question, she smiled gloriously and said, "Sports is crazy."