Checkmate: Courier Out in 3rd Round : Wimbledon: Qualifier Olhovskiy ruins Grand Slam plans with four-set victory. That opens up draw for McEnroe, who rolls over Wheaton.

At Wimbledon Saturday, tennis discovered Andrei Olhovskiy, a 26-year-old chess-playing Russian with more syllables than victories this year and a ranking about the same as the temperature of a boiled egg.

Ranked No. 193 and apparently going nowhere in a career most noted for the fact that he plays tennis at the same sports club in Moscow where Anatoly Karpov plays chess, Olhovskiy pulled off one of the biggest upsets in decades at Wimbledon.

He beat No. 1-ranked and top-seeded Jim Courier, 6-4, 4-6, 6-4, 6-4, in a third-round shocker that not only ended Courier’s streak of titles at four but also stopped his chances for the Grand Slam.

And how did you do it Andrei?

“I don’t know,” he said.

So there you have it. A guy who can’t win beats a guy who can’t lose and then can’t explain it.

But this much fallout is known for sure--it is the first time at Wimbledon since the open era began in 1968 that a qualifier has toppled the No. 1-seeded men’s player.

A man of few words and victories--he had four in 1992 before Saturday--Olhovskiy explained what happened:

“You know, life is life, you know?”

Courier knows. Halfway to the Grand Slam and halfway to the fourth round, Courier fell flat on his grass-court game because he had problems returning Olhovskiy’s serve.

At times, Courier looked as if he would have had a problem returning a letter. He was still looking shaky on both sides of the net in the fourth set when Olhovskiy forced a break point, then cashed it in when Courier dumped a sitting-duck forehand volley into the net.

Said Olhovskiy: “Maybe he was nervous . . . just at that point.”

And after the changeover, Courier was gone. Olhovskiy served out the match with ease.

In the face of such a complete dismantling, Courier still managed to be gracious. If he he didn’t hit many returns, he also didn’t use a single excuse.

“I got outplayed,” Courier said.

So did David Wheaton. John McEnroe, 33, continued to celebrate his 14th Wimbledon in successful fashion, following up his stirring five-set victory over Pat Cash with a straightforward, 6-3, 6-4, 6-4, number on Wheaton, 23.

Derrick Rostagno and Byron Shelton double-faulted on match point and shared the same result--they lost.

Andre Agassi got to the fourth round with a 6-3, 7-6 (7-5), 7-5 decision over Rostagno, and Shelton gave Boris Becker a scare before losing, 6-4, 3-6, 7-6 (7-5), 7-6 (7-5). Becker reached the fourth round for the seventh time in nine years.

Guy Forget, Wayne Ferreira, Jeremy Bates and qualifier Christian Saceanu also advanced.

Olhovskiy’s Wimbledon experience has not been nearly as rosy as Becker’s. This is Olhovskiy’s fourth Wimbledon, and for the fourth time he had to come through the rigors of qualifying.

He had to win three matches to get in, including a five-set endurance contest against Mario Tabares in the last qualifying round.

Until winning his first-round match against Jonathan Stark in the main draw at Wimbledon, Olhovskiy had lost his last four first-round matches.

“Yes, I lost, but I lost to guys who play not so bad,” he said. “I tell you about guys (ranked) 200 and top guys, it’s no big difference. . . . It’s in the head, you know.

“If you feel confident, you can play very well. That’s what I feel now.”

Olhovskiy began playing tennis at 9 and practiced at the CSKA Club in Moscow, famous for Karpov’s checks as well as the cross checks by the Red Army hockey team that made the club its home base.

A four-time Russian doubles champion, Olhovskiy learned how to play fast surfaces when he practiced on wood and plastic courts that were sometimes all the financially strapped Russian Tennis Federation could provide.

He turned pro in 1987 and immediately embarked on a wildly erratic ride through the rankings, from No. 360 to No. 86 back up to No. 302.

Victor Yanchuk, Olhovskiy’s coach for the last year, said there is a reason for such an up-and-down ledger.

“It’s a question of psychology,” Yanchuk said. “Now, he is playing for himself, not the federation. It has helped him develop inspiration and confidence.”

At ease on the grass court, the 6-foot-1 150-pound right-hander meets McEnroe next, but after what he has already been through, Olhovskiy isn’t planning on being intimidated.

“It’s not difficult to play the next match because I play well in the tournament, and the next match will be the same,” he said. “I play against somebody who will play against me--not the name. I’ll just play my game.”

* GRAF ADVANCES

It takes three sets, but the second-seeded player reaches the fourth round with a victory over Mariaan de Swardt. C6