For Mats Wilander, this Wimbledon soon will be a dim, sad memory. For Slobodan Zivojinovic, this Wimbledon has become a fantasy he is not likely to forget. And for the rest of the tennis world, this Wimbledon is rapidly becoming more a siege than a tennis tournament.

Today, the sun actually made an appearance before sunset, shining through shortly after 2 p.m. It stayed only about an hour, disappearing behind dark clouds again as the players retreated to the locker rooms.

But the rain didn't come in time for Wilander. As the sun peeked into Centre Court, Wilander found himself at the mercy of Zivojinovic, a strapping Yugoslav with a huge serve and surprising touch. In a stunning display of serving and shotmaking, Zivojinovic swept the fourth seed and French Open champion out of the tournament, 6-2, 5-7, 7-5, 6-0, then won the crowd by bowing to all sides and waving joyously to his fiance and his brother after match point.

"This is a dream," Zivojinovic said. "Monday, when I first came here, I thought this must be a dream that I am going to play on Centre Court at Wimbledon. I dreamed of it since I was 7 years old. Now, to beat a great player like Wilander, it is not a dream anymore, it is real."

The realities of grass also were in evidence on the outside courts, where 10th-seeded Aaron Krickstein, playing his first pro tournament on grass, lost to big-serving Bud Schultz, 6-4, 3-6, 7-6 (7-3), 6-4. Schultz, 6 feet 4 and a former Bates College basketball player, overpowered Krickstein with his aggressive serve and volley. Krickstein never had a chance to wind up for his whipsaw ground strokes, baffled often by the low grass bounce and the skidding Schultz serve.

Schultz is 25 and never played in a tennis tournament until he was 20. He has just broken into the top 100 on the computer, and on this surface his victory was hardly a shock.

Krickstein was the only other seed to lose among the men. The only seeded woman to lose was 12th-seeded Caterina Lindqvist. She lost, 6-0, 7-5, to Barbara Potter, a Connecticut lefty who has been a U.S. Open semifinalist and missed being seeded by one spot on the computer.

Other seeded men did have problems. No. 5 Anders Jarryd came from two sets and a break down to beat Claudio Panatta, 4-6, 3-6, 6-4, 6-4, 6-3, playing the fifth set just before darkness today after darkness had halted play Tuesday. Yannick Noah, the 11th seed, easily could have lost to Brad Gilbert, but escaped, 6-3, 3-6, 7-6 (8-6), 6-7 (5-7), 6-3.

Other seeded players had less trouble. Jimmy Connors, taking the court at 7:30 p.m. because of the delays, made short work (80 minutes) of Stefan Simonsson, beating him, 6-1, 6-3, 6-4. Seventh-seeded Joakim Nystrom, No. 9 Johan Kriek, No. 13 Eliot Teltscher, No. 14 Stefan Edberg and No. 16 Tim Mayotte also won. The only women's seed who made it to the court other than Lindqvist was No. 8 Zina Garrison, a 6-2, 6-1 winner over Elna Reinach.

But the match of the day was Zivojinovic-Wilander. Zivojinovic is 6-6 and 200 pounds and probably would make a wonderful outside linebacker with his quickness (his time in the 40 was unavailable) and grace. He is 21, handsome, gregarious and, at least today, a brilliant tennis player.

Wilander, coming off his victory in the French Open, was thought by many to be the main threat to John McEnroe here. He has won the last two Australian Opens on grass and even though it is not his favorite surface, he plays well on it.

"I never felt I was into the match today, though," he said. "When I saw my draw, I knew it would be a tough match because he is such a good server. For me to win today, I would have to have been very lucky. I wasn't. It's disappointing because I was confident I would have a good tournament here."

Wilander was in trouble almost from the moment he stepped onto Centre Court. Zivojinovic raced through the first set in less than 30 minutes, hitting one rocket serve after another past Wilander. Considering that Wilander might have the best return in tennis, this was no mean feat.

Wilander seemed to find a rhythm in the second set, his returns often coming back at Zivojinovic as hard as they had been served. He won the set with a superb game at 6-5, coming back from 40-0 with the aid of a double fault. At deuce, Wilander snapped off two winners, the last a forehand down the line for the set.

That, it seemed, would be the end of Zivojinovic's dream. Wilander now would do what four-time Grand Slam champions usually do with players nicknamed "Bobo" who are ranked No. 77 on the ATP computer.

Except Wilander ended up in the Bobo role. Zivojinovic is a player with credentials, having beaten Pat Cash earlier this year before reaching the semifinals in a Wimbledon prep tournament two weeks ago. He never seemed rattled by his surroundings or the stature of his opponent, whom he played three times as a junior, winning once.

At 5-all, Zivojinovic broke, chipping a backhand off a short ball, then attacking and watching Wilander's backhand sail wide. He served out the set at love and embarrassed Wilander in the last set, giving up only 12 points while never facing so much as a game point.

"By then, he was hitting all the shots so well I knew I was probably dead," Wilander said. "Grass can be frustrating. You get a guy 15-30 and they hit two big serves and your chance is gone before you even hit a ball. He did that a lot today."

Zivojinovic served 16 aces and uncountable service winners. He also showed a deft touch on his drop shots, and by the fourth set was whipping backhands all over the court as Wilander watched helplessly.

"I can serve better," said Zivojinovic, who has been coached this year by Wojtek Fibak, Ivan Lendl's former mentor. "I am still trying to improve my game. Right now, tennis is the most important thing to me."

Zivojinovic's intensity was apparent as he took command. After several big points, he shook his fist towards the Friends Box where his fiance and his brother Ceda, a teaching pro in Hamburg, were seated. "This is a very big moment in my life."

It was also a big moment for Wimbledon, which still is less than halfway through the first round after three days of play. The tournament committee finally conceded this evening that the schedule was a bit backed up, moving the start of play on all courts up to noon for the next three days -- "weather permitting."

If the weather doesn't permit soon, the final might take place on Labor Day. By then, Zivojinovic's feet might be back on the ground.