With a staggering serve and a theatrical curtsy, 18-year-old American Alexandra Stevenson made history at Wimbledon today with a 6-3, 1-6, 6-3 quarterfinal win over 16-year-old Jelena Dokic.

The victory moved Stevenson into a semifinal matchup against fellow Southern Californian Lindsay Davenport. She is the first qualifier to ever reach the women's semifinals here; John McEnroe reached the men's semifinals as a qualifier here in 1977.

"I just think it will be a great match -- good for American tennis," Stevenson said. "I've been waiting for this my whole life, and it's very exciting."

Dogged by outside controversies almost since her arrival here, Stevenson has remained focused on tennis to maintain her incredible run. She has yet to defeat a seed, although she found a more than worthy adversary today in Dokic, the Australian qualifier who upset top seed Martina Hingis and No. 9 seed Mary Pierce earlier in the tournament. Rain delays extended their match over two days, and while Stevenson took the first set easily, Dokic looked sharp in the second.

The third set, which made up the bulk of today's play, turned when Stevenson broke Dokic to go up, 4-2, and then held her next service game. She finished the day with 15 aces to Dokic's 1, pleasing the crowd after the match by curtsying toward the stands.

"She's great; she's been a breath of fresh air to the whole women's game," said Craig Kardon, Stevenson's coach here. "She's a sponge. She keeps impressing me every day."

Croatian teenager Mirjana Lucic also advanced to the semifinals today with a 4-6, 6-4, 7-5 win over Nathalie Tauziat. Lucic will play Steffi Graf, who defeated Venus Williams in a quarterfinal match Thursday.

All-American Lobby

The July 16-18 Davis Cup matchup between the United States and Australia may look a lot different than originally planned. Jim Courier and Todd Martin were supposed to fill the two singles slots for the Americans, but today Martin said he thinks Pete Sampras should play singles. Sampras had originally declined to play Davis Cup, leaving Courier and Martin to pull an upset victory over England in April, but he changed his mind last month. In the spirit of teamwork, Sampras said he would play doubles, but Martin thinks leaving one of the world's top players out of the singles competition would be a major mistake.

"I would volunteer" to give up the singles slot, Martin said. "I think Pete should be playing singles. . . . I want our best team on that court."

Patrick Rafter and Mark Philippoussis had planned to play the singles matches for Australia, but Philippoussis tore cartilage in his knee today in a match against Sampras. He will be out 4-6 weeks and miss the Davis Cup entirely. The Australians likely will field 18-year-old Lleyton Hewitt in his place. Hewitt has had an excellent summer, despite losing to Boris Becker here in the third round.