WIMBLEDON : No. 2 Edberg, No. 3 Stich Aced Out of Quarterfinals : Tennis: Ivanisevic and Sampras advance. McEnroe, Agassi leading.

They are 20, they knock the fuzz off the ball, they have no respect for authority and they are in the semifinals at Wimbledon.

Pete Sampras and Goran Ivanisevic, who treat the tennis ball as though it had done something to annoy them, slam-dunked their way past two former champions on a cool, wet, dreary Wednesday at the All England Club.

Sampras steamrollered defending champion Michael Stich in straight sets, and completed a stunningly routine 6-3, 6-2, 6-4 victory before the gel in his slick-backed hair had time to dry.

Stich, seeded third, said what fifth-seeded Sampras did to him was a crime.

“He just killed me,” Stich said.

If so, the lethal weapon was a mid-sized graphite model that pretty well matched the one eighth-seeded Ivanisevic used on two-time champion and second-seeded Stefan Edberg.

Ivanisevic, a 6-foot-4 ball-wrecking, nerve-racking left-hander, launched 33 aces past Edberg and won a five-set experiment in serving terror, 6-7 (12-10), 7-5, 6-1, 3-6, 6-3.

As far as Ivanisevic is concerned, Wimbledon is simply one big, grassy fairway and he isn’t the least bit afraid to leave a divot here or there. With 136 aces at this juncture, Ivanisevic is regarded as owning the premier serve in tennis, even if he has trouble explaining how he does it. Said Ivanisevic: “It’s just hitting.”

All in all, it was a typically straightforward day of Wimbledon tennis. Two guys with big serves won and, of course, it also rained, interrupting the two other quarterfinal matches.

After nearly two hours of a rain delay, play was called off just before 7 p.m., which means Boris Becker and Guy Forget get a chance to think about how to come back against Andre Agassi and John McEnroe.

Agassi led Becker, 4-6, 6-2, 6-2, 3-4, but was down a break in the fourth set. McEnroe held a 6-2, 5-5 lead over Forget. Both matches are scheduled to be completed today with the winners to meet in the semifinals Friday.

Sampras and Ivanisevic match serves in the other semifinal.

In only his fourth Wimbledon, Sampras is a semifinalist for the first time. And he got there with a rout of Stich. It took only 58 minutes for Sampras to win the first two sets and five games for him to get the only service break he needed in the third set.

With Stich serving at 15-40, Sampras took a short ball and directed it cross court for the break. Sampras held at love for 4-2, the last point on a service winner down the middle that dribbled off the end of Stich’s racket.

After that, it was a matter of serving out the match, which seemed to come easily to Sampras--nearly as much as his new-found ability to return the ball on grass. Sampras had seven winners on returns; Stich had none.

“I think (my) biggest (problem) the last couple of years was my return of serve,” Sampras said. “You know, you would think grass would be a good surface for me.”

Tim Gullikson, Sampras’ coach, certainly felt that way, so he drilled Sampras for the last two weeks on how to knock back serves on grass.

“The problem I had in the past, being from California (and playing mostly on hard courts), I have pretty long, gangly strokes on grass,” he said. “You have to shorten them up. I was working (with Gullikson) to shorten my swing.”

It took Sampras little time to end the match. Serving for the match at 5-4, Sampras bounced the ball three times and unloaded a service winner to Stich’s backhand. At 15-0, Stich fanned on a low forehand. At 30-0, Stich mis-hit a return on a second serve and sent it wide.

Stich saved one match point when Sampras double-faulted, but Sampras scored on another service winner to Stich’s backhand and it was over. Sampras had nine aces, dozens of service winners, averaged 118 m.p.h. on his first serve, saved the only break point against him and dominated the defending champion.

The whole experience required 1 hour 27 minutes, which Stich found just long enough to get his crown handed to him.

“He was just too good for me,” Stich said. “ . . . He just played perfect grass-court tennis.”

Ivanisevic’s upset of Edberg ended the 26-year-old Swede’s hopes of keeping intact his habit of winning Wimbledon every two years. Edberg beat Becker in the final in 1988 and 1990.

Edberg didn’t have many chances against Ivanisevic’s serve. He broke once in seven chances and was unlucky enough to lose points on three balls that hit the net in the final game when Ivanisevic was serving out the match.

Other than that, it was a thoroughly enjoyable day for Edberg, who said Ivanisevic probably ought to continue his tactic of not thinking when serving.

“He just goes out and hits it,” Edberg said. “That’s all he does. He bounces it once or twice and then, boom!”

As the tournament has progressed, Ivanisevic has developed a reputation for delivering the best quote as well as the best serve. For example:

Question: Is this the best you can serve?

Answer: “It’s only 33 aces; it’s not so good.”

Q: What has been different the last week?

A: “I’m not getting crazy.”

Q: How would you describe the person you studied on video of some of your past matches?

A: “Some guy who came from another planet.”

Sound pretty strange? After Wednesday at Wimbledon, only one fact is certain about both Ivanisevic and Sampras. Their serves are from another planet.