U.S. OPEN : Sampras Wraps Up Chang With a Complete Package : Tennis: After being swept in first-set tiebreaker, 1990 champion turns on power to reach semifinals.

What can you possibly do when you are on the other side of the net and Pete Sampras is knocking tennis balls so fast that you feel like you’re standing on the runway at LaGuardia?

It is a question Michael Chang asked himself late Wednesday night at the U.S. Open, where a day of rain ended in a hail of tennis balls and a flash of Sampras’ racket.

Sampras, the youngest U.S. Open champion at 19 three years ago, put himself into position to win it again at 22 with an impressive 6-7 (7-0), 7-6 (7-2), 6-1, 6-1 victory over Chang in a 3-hour 1-minute quarterfinal under the lights.

It was almost like a race for Sampras, who spotted Chang a set lead, evened it up, then took off on the anchor leg and won the last two sets in one hour.

So overpowering was Sampras, he won 11 consecutive games, 13 of the last 15, lost one point on his serve the final two sets and had Chang scratching his head and wondering what he possibly could have done to turn it all around.

“Go over there and snap his strings?” Chang said. “I don’t know. Maybe get Princess Di over here.

“Pete is probably one of the most complete players out there, probably one of the most talented, if not the most talented out there. Pete can do everything.”

It seemed pretty apparent that Sampras went through his entire repertoire in the last two sets in the most dominating period of an important match at the tournament.

Until Chang held for 1-5 in the fourth set, he had won five points in the set.

At the same time, Sampras was winning with everything in the book, including a 100-m.p.h. second-serve ace, a bone-chilling first-service return that had the ball bouncing into the stands almost before Chang could move and cross-court shots with such an edge they could have drawn blood.

Sampras was playing in a zone. And there was no zone defense.

“When I am playing my best tennis, I basically don’t think,” Sampras said. “I just react and don’t really think about what I’m doing--that sounds a little bit weird, but you know, I just go for it.”

So off he went into the semifinals for the third time in the last four years, although Chang’s perfect first-set tiebreaker made it seem as if Sampras wasn’t going anywhere but back to Florida.

A double fault (one of seven by Sampras to go along with 13 aces) gave Chang a 3-0 lead in the tiebreaker, which ended when Sampras mashed a backhand into the net.

Down a set, Sampras had a chance to close out the second set early, but he lost his serve at 5-3 and went to another tiebreaker. This one he started with an ace and ended with a 125-m.p.h service winner.

Sampras said he just got off to a slow start.

“Michael was taking the match to me. . . . I was staying back,” he said. “That is just not my style. I had to (change). The last two sets were probably the best two sets I played in a very long time.

“Hopefully I can play as well (in the semifinals) on Saturday as I did tonight.”

Sampras will face Alexander Volkov, who defeated Thomas Muster, 7-6 (8-6), 6-3, 3-6, 2-6, 7-5, but Chang isn’t convinced Sampras can play much better than what he had witnessed first-hand.

“I think even if I was up two sets to love, I probably still would have lost the match,” Chang said.

That is, of course, unless he really had gone over there and snapped Sampras’ strings.