Last year, within minutes of losing the most spectacular and memorable match of the century Wimbledon tennis match championships to Bjorn Borg, Vitas Gerulaitis bounded into the press room at the All Lawn Tennis and Croquet Club and launched into a hilarious monologue about the pecularities of British life and Wimbledon traditions.

After about 10 minutes, someone interrupted to ask how he could be so gay after a heartbreakingly narrow loss, 8-6 in the fifth set, in the biggest match of his life.

Gerulaitis ran a hand through his tousled blond hair and flashed the familiar grin, at once smart-alecky and endering, that has won him friends and influenced people since he was a streetwise youngster growing up in Brooklyn and Queens.

"I'll tell you the truth," he said."This was my winning speech, and I didn't want to waste the good material."

There is nothing sullen or morose about Vitas Kevin Gerulaitis, 23, who again has reached the Wimbledon semifinals and plays Jimmy Connors today. Borg, seeking to become the first man since Fred Perry 1936 to win three consecutive Wimbledon singles titles, opposes unseeded Tom Okker in the other semi.

Gerulaitis won the Italian and Australian opens last year, and the World Championship Tennis Finals at Dallas in May, but he knows he has to win either Wimbledon or the U.S. Open to gain admission to what he calls "the two-mile high club" - the uppermost echelon of the game currently inhabited by only three men: Borg, Connors and Guillermo Vilas.

He woould be a flamboyant addition to the club, not only becausee of his flashy game - based on speed afoot and quickness around the net - but because of his effervescent personality and flair for showmanship.

Gerulaitis has an appealing New York brashness and a grandiose sense of style. His hobbies are cars and partying, and he has a zest for both.

The garage of his ornate house in King's Point, N Y., currently stables two Rolls-Royces (a White Corniche and a Silver Cloud), a Mercedes, a Porsche and a Ferrari.

"They're like my children. I baby them. My Chroniche gets treatment that some my girlfriends would like to have," he says. "If Dom Perignon made motor oil, that's what they would get."

Not that his girlfriends do badly. Gerulaitis is a regular in the most fashionable night spots in New York when he is at home. He dines at Elaine's and dances until dawn at Studio 54. He does not seek out publicity, but it finds him. He is the tennis star of the gossip columns. Joe Namath with a racket. They call him "Broadway Vitas."

Of course, he doesn't do anything to play down his image. After winning in Rome last year, he threw a victory party at Jackie O's, the "in" disco on the Via Veneto. He arrived in a chaffeured limousine, wearing a Gatsbyesque white linen suit, with a lovely lady on each arm.

This week, when an Australian journalist asked him if he planned to defend his Aussie championship in December, Geralaitis said it depended in part on whether or not a proposed pro-celebrity event is arranged.

"I told the promoters that if I can play doubles with Olivia Newton-John, I'd be there for sure," he said.

Gerulaitis' fun-loving life style does not interfere with his tennis, however. He has been working hard to improve his game, especially his serve - once a glaring weakness, but now his serve-once a galring weakness, but now much more formidable - and the variety of his volley.

He has been training hard, running and exercising, under the supervision of Australian Fred Stolle, his coach on the New York Apples of World Team Tennis. He is thinking about retaining Stolle as his full-time coach after the team tennis season, "to polish up the other parts of my game," he explains.

He wants to make that last professional leap up to the company of Connors, whom he defeated the first time they played, in 1972, but not in 10 meetings since, and Borg, with whom he has played some superb matches but never won in eight meetings.

"I'm getting closer. I may still need some work, but I think now I have the confidence. I know I can win a tournament like Wimbledon," says Geralaitis, who has been practising daily with Borg.

"I'd like to win it, just to satisfy my own ambitions. I don't feel I have to prove anything to anybody else. I'm almost content with where I am right now - I make a comfortable living, I enjoy myself - but I still would like to make that leap because I think I can do it and I don't want to disappoint myself.

"I sued to have a "please-everybody" attitude. I wanted to make everybody happy, but I finally realized that no matter what I do the rest of my life, some people are going to love it and some people are going to hate it.

I'd love everybody to like me, but some people are going to be jealous, some are going to say even before they know me, "Look, there's that flashboat from New York, the showoff with his fancy cars and his broads."

So now I live my own life and try only not to disappoint myself."

Gerulaitis also is able to step back from the pressure of the pro tennis circuit, which has turned so many players into unsmiling robots, and look at his existence with a refreshing perspective.

"I was practicing with Borg last weekend, and was getting really hacked off in the wind. It was like a gale. I'd toss the ball up to serve and it would blow over the fence. I was about to break my racket in frustation when I kind of remembered that it's just a game, and I'm very fortunate to be playing it." Gerulaitis says.

"I got a letter recently from a blind couple who wrote to say that they had been following my career and hoped I won Wimbledon. It was really a moving note. That kind of thing brings you back to earth when you figure you'll commit suicide if you lose a match."