Vitas Gerulaitis had just disposed neatly of Jose-Luis Clerc, who will be one of his singles opponents in the U.S.-Argentina Davis Cup series at Memphis the weekend after next, 7-6, 6-2, 6-2, to reach the quarterfinals of the U.S. Open tennis championships.

Now he was thinking ahead -- though not looking past his next foe, the fleet and flashy Johan Kriek, he emphasized -- to a possible semifinal rematch with Bjorn Borg, who played raggedly until he got in trouble today and then lifted his game to beat Dick Stockton, 6-4, 1-6, 7-6, 7-5.

Gerulaitis, a flamboyant 25-year-old New Yorker, has little cause to be optimistic about halting his frequent practice partner Borg's march toward the third leg of a possible French-Wimbledon-U.S.-Australian Grand Slam.

They have played 13 times in competition, and Borg has won all 13. The most memorable was the 1977 Wimbledon semifinal, an all-time classic of inspired shotmaking, which Borg won by the breadth of one of his scraggly whiskers, 6-4, 3-6, 6-3, 3-6, 8-6.

Borg has won 14 of the 15 sets they have played since last year's Open, when the Swede was a 6-3, 6-2, 7-6 victor. Their latest meeting was in the semifinals of this year's French Open, and Borg made Broadway Vitas blush as red as the Parisian clay, 6-2, 6-1, 6-0.

In all, Borg has dominated Gerulaitis in 25 of 29 sets since that magical day at Wimbledon 26 months ago when they seemed so close in skill and spirit.

Some people think that Gerulaitis is hopelessly psyched out against Borg, a pigeon whose inferiority complex on the court is only increased every time he gets bludgeoned in practice.

Gerulaitis, predictably, disagrees. "I have to paly a couple of hours a day just to stay sharp, and actually Bjorn is a good guy to practice with because he really just punishes my serve, and I have to do a lot of work to keep holding it," he said.

"Then when I play somebody like Clerc -- he's a couple of classes below Borg, but he plays very similar, Topspin shots -- the serve I hit to Borg and he gets back is maybe a winner against him. So that's good when I play this guy, because if I don't beat this guy I don't get to play Borg a couple of rounds down the road."

Got that?

Gerulaitis was chipper, typically flip and engaging, after escaping a tight first set (he never had a break point, but was sharp in the tie breaker) and then running through Clerc, 21, a rapidly improving player who is ranked No. 12 in the world and was seeded 10th in the Open.

This was the first time they had played and Gerulaitis knew that Tony Trabert, U.S. Davis Cup captain and a CBS-TV commentator here, would be watching for a sneak preview of what could happen when Clerc and countryman Guillermo Vilas take on Gerulaitis, John McEnroe, Stan Smith and Bob Lutz in the Davis Cup quarterfinals on an indoor court in Memphis, Sept. 17-19.

"That put a little more pressure on me," acknowledged Gerulaitis. "Maybe I was a little bit tight in the first set. I didn't expect him to serve so well, so he caught me off guard . . . But I hung in there and served really well the last two sets. You have to serve pretty well and get into the net quickly against a guy who returns with a lot of topspin the way Clerc does."

Gerulaitis has exceptional speed and agility at the net, but has been just a trifle too light of shot to rise from his No. 4 ranking and challenge Borg, Jimmy Connors and McEnroe, the current troika at the pinnacle of the game. He has been working on his serve all summer, especially since his devastating first-round loss to Pat DuPre at Wimbledon.

Mostly he has been working on it on his own, with assists from his Australian coach, Fred Stolle, and his friend Arthur Ashe. "Arthur gave me a few pointers on it when we were together for a week in Kitzbuehel (Austria)," Gerulaitis said. What was the profound advice? "Mainly, 'Hit it harder,'" Broadway Vitas said with a stage laugh. "Arthur's a great instructor."

If Gerulaitis -- winner of one Australian Open, one World Championship Tennis finals, and two Italian Open titles -- ever wins the Open, the parties would last a week. "He probably wouldn't win another match for a year, he'd go so wild," his business adviser, Bob Kain, joked today.

Gerulaitis thinks he is playing well enough, and peaking on the proper schedule, to win.

First he must play Kriek, 21, who may be the swiftest player in the game today -- speedier afoot than even Borg and Gerulaitis. Kriek today won a splendid match against charismatic Yannick Noah, who was discovered by Ashe during an exhibition tour in Cameroon eight years ago, 6-3, 7-6, 4-6, 1-6, 6-4. But Gerulaitis handled him easily in the quarters here last year, Kriek's "breakthrough" tournament, 6-2, 6-1, 6-2.

Assuming he again leaves Kriek upstream without a paddle, Gerulaitis would probably play Borg or Roscoe Tanner, the Wimbledon runner-up. At the risk of being called a masochist, he insists he is looking forward to it.

"I'm serving and volleying well, playing aggressively, improving every match," he said. "I didn't serve anywhere near as well last year and I got to the semis. I'm volleying more aggressively, putting a few more balls away at net . . . I'm feeling pretty confident right now."

Confident enough to win the Open?

"Confident enough to beat Borg in the semis, and I think that would be nine-tenths of the battle, because he's the guy that's playing the best," Gerulaitis said. "I've watched a couple of his matches and I've practiced with everybody else except Connors this week, and Borg's by far hitting the ball better than any of the other players."

This was before Borg was pressed to the hilt by Stockton. Seldom has the Swede mis-hit so many balls in a match, but he was solid as Gibraltar on the crisis points. Still, of the men already into the quarters, Gerulaitis is now the only one who has not lost a set. Connors and Harold Solomon, who play their fourth-round matches Tuesday, have gone through three rounds without yielding a set.

When one fine player has lost to another as consistently as he has to Borg, Gerulaitis was asked, doesn't he figure the law of averages has to catch up eventually?

"I thought about that the last eight times I played him," Gerulaitis said, shaking his leonine blond locks. "But he is far and away the best player in the world now. He's almost got a record to match Rod Laver's, and I thought nobody would have the record Laver had in the modern era of tennis."

Is Borg the best player of all time?

"I haven't played Bill Tiden," Gerulaitis grinned, "but I watched Rod Laver a couple of times when I was a teen-ager, when he won his second Grand Slam by beating Tony Roche on a rainy day at Forest Hills, and I tell you he played an unbelievable match that day. It would be a hell of a match, Laver and Borg at their best. But I think day in and day out, especially on slow courts, Borg may be a better player. And I really admire Laver and hold him as an idol."

Gerulaitis has thought about the day he will beat Borg. He knows what he will have to do: pressure him relentlessly from the net, break up the Swede's rhythm from the back court, never give him two balls in a row of the same pace and spin, and not miss any easy shots.

"You just get overanxious against him, because when you get a duck shot you want to make sure you put it away, and so then sometimes you overplay shots," Gerulaitis said.

"But you have to overplay a lot of them because he just gets to so many. And the guy goes for a passing shot no matter where he is on the court. He rarely plays a defensive shot. You can have him 30 feet off the court, and he'll go for a topspin backhand pass. There are not many guys who can do that. In fact I don't know of any other guys."

Gerulaitis, a great crowd favorite in Europe, is puzzled that he has never been able to capture the support of his hometown audience in New York.

"I will walk from the locker room to the front door here and I must see 10,000 people, and they all say 'We're cheering for you, we'll be with you, don't worry.' Then I go out there and I don't hear one person say, 'Let's go, Vitas," he said. "I think, where the hell did these 10,000 people go? Did they all leave? Don't they have tickets?

"It's the same thing with McEnroe. He's from New York, but we'll never get anybody behind us until we play David Berkowitz or somebody like that. Then we might have a chance.

"I don't know why. I'm maybe just a notch above Mac, and he's maybe a notch above 'Son of Sam.' But I guess in America everybody roots for the underdog," Gerulaitis went on.

"Maybe if I play Borg they'll root for me because they feel sorry for me. But it won't be because I'm the hometown favorite . . . I would think, whether the fans like McEnroe and me or not, they'd be rooting for us since we're representing New York, we're proud to be born and raised in New York. And then we go out there and everybody is rooting for Tito Rodriguez, from the Pampas . . . "