Agassi Takes One More Giant Step : Tennis: Unseeded Andre routs Muster with an attack that propels him into U.S. Open semifinals.

He is only 5 feet 11 and 170 pounds, but to Thomas Muster, he had to look like Andre the Giant. Not only did Andre Agassi beat Muster in the quarterfinals of the U.S. Open tennis tournament Wednesday night before a Stadium Court crowd of 20,571, but in the process he turned Muster into the incredible shrinking Austrian.

In the face of Agassi’s eye-of the-needle shotmaking, Muster’s big baseline game became little. As the match wore on, Agassi’s attacks moved deeper and deeper inside his baseline, and Muster kept retreating deeper and deeper behind his. Soon Agassi, suddenly the Paul Bunyan of this tournament, had run off a 7-6 (7-5), 6-3, 6-0 victory by blasting one of the toughest baseline players in the game right off the court.

“The harder I played, the faster the ball came back,” said Muster, seeded 13th. “After the tiebreaker in the first set, he hardly missed a shot.”

Agassi, unseeded here because he had surgery for a wrist injury late last year and has struggled to get his game back to its previous top-10 level, gained a semifinal berth against methodical Todd Martin, the No. 9-seeded player, who marched steadily through a 6-4, 7-6 (7-5), 4-6, 6-4 victory over Bernd Karbacher of Germany.

The other men’s semifinal matchup will be settled today, when Jaime Yzaga of Peru, upset winner over top-seeded Pete Sampras, takes on Karel Novacek of the Czech Republic and fourth-seeded Michael Stich of Germany plays Jonas Bjorkman of Sweden, upset winner over fifth-seeded Stefan Edberg.

Friday’s women semifinalists were also determined Wednesday, when top-seeded Steffi Graf of Germany and seventh-seeded Jana Novotna of the Czech Republic joined Tuesday winners second-seeded Aranxta Sanchez Vicario of Spain and eighth-seeded Gabriela Sabatini of Argentina. Graf zipped past 11th-seeded Amanda Coetzer of South Africa, 6-0, 6-2, and Novotna routed fourth-seeded Mary Pierce of France, 6-4, 6-0.

Agassi, although unseeded, is certainly not unfavored, especially after a run that has made him one of only seven unseeded men in history to beat three seeded players in this tournament. Coincidentally, the first on that list, in 1930, is Francis X. Shields, whose granddaughter, movie star Brooke, is Agassi’s girlfriend and loudest courtside rooter in each match.

Like Jimmy Connors in 1991 and George Steinbrenner every day, Agassi has captured New York. The tabloids have started spreading the news. It looks as if Agassi can make it here, can make it anywhere, the way he is playing.

“I’ve said it a lot here--probably too much,” Agassi said, “but to be quite honest, I feel I can win these matches. . . . Nothing matters when you get to the semis of a Grand Slam except that you are there. . . . Nothing matters except Saturday, and there’s nothing like Super Saturday. I can hardly wait to get out there.”

Muster agreed that Agassi’s chances are great, and so did every other player who has faced him on the court in this tournament and then come to the interview room afterward and faced the press.

“I think Andre has a great chance to win this championship,” Muster said, “and it’s the best I’ve seen him play in a long time.”

This was supposed to be a rematch of sorts of the French Open quarterfinal the two played in May, won in five long sets by Muster, the master of clay. Muster has won 23 tour events in his nine years on the tour, 22 of them on clay.

“On clay, I could slide for his shots and run them down,” Muster said, “but it’s much harder for me to run on hardcourts.”

Part of the reason for that is because of the injury Muster suffered the day he reached the final of the 1989 Lipton. He was struck by a car in a parking lot shortly after his semifinal victory and underwent serious surgery on his left knee.

Another part of the reason for that, however, was Agassi’s tremendous hardcourt skills. The 24-year-old from Las Vegas has won 21 tour events, and 13 of those have been on hardcourts like those at the U.S. Open.

Ironically, on a night when Agassi needed little help, Muster gave him some in the ninth game of the second set. Muster was serving at 3-5 and deuce when Agassi hit a shot that was called long, giving Muster a game point. But Muster thought the ball had hit the baseline and refused to take the point. Finally, the chair umpire announced, “Mr. Muster has asked to replay the point.”

When they did, Agassi got it. He then broke Muster’s serve on the ad point and ran through the third set in 22 minutes. From the moment Muster replayed the point in the second set until Agassi finished him off at match point in the third with a big inside-out forehand, Muster won only 10 more points.

“We are good friends and I don’t think I could steal a point like that,” Muster said.

Agassi added: “That just shows the kind of guy Thomas Muster is.”

Or was, before Agassi shrank him.

Notes

The quest for a women’s Grand Slam in doubles stayed alive when Gigi Fernandez and Natalie Zvereva beat Katrina Adams and Manon Bollegraf in the quarterfinals, 6-2, 6-2. Last year, they lost in the semifinals here after winning the Australian, French and Wimbledon titles, the same three they’ve won this year. . . . Meilen Tu of Northridge, seeded fourth in the junior girls’ tournament, won her second consecutive match, beating Karin Palme of Mexico, 6-1, 7-6 (7-4). . . . Amanda Basica of Rolling Hills, the 11th-seeded player, was upset by unseeded Surina de Beer of South Africa, 6-2, 6-4.