MELBOURNE, Australia -- Karol Kucera defused Pete Sampras' usually deadly service game with flashy returns in a four-set victory, leaving the Australian Open without its top five seeds even before the semifinals.
A rash of forehand errors by Sampras contributed to the defending champion's 6-4, 6-2, 6-7 (5-7), 6-3 loss to the unseeded Slovak. Kucera had 18 aces, to just seven for Sampras.
"It's disappointing, sure it is, this is what I'm playing for,'' said Sampras, who puts his major effort in to the Grand Slams. "The way he played, I didn't expect it. He really put a lot of pressure on me. He served much better than I thought.''
Sampras added, "I dug myself a hole. ... He played a match of his life."
Spain's Alberto Berasategui earlier had eliminated No. 2 Patrick Rafter and another crowd favorite, former No. 1 Andre Agassi.
The only remaining seeds are No. 6 Petr Korda -- Kucera's next opponent -- and No. 9 Marcelo Rios, who plays Berasategui in the quarterfinals Wednesday.
Kucera, who upended Australia's Richard Fromberg, 6-2, 3-6, 6-2, 7-5 on Sunday, might be the hottest player on the men's tour. The 23-year-old began the year by guiding Slovakia to victory in the Hopman Cup, a mixed team event, then captured the Sydney International last week, vaulting him to 20th in the world.
Sampras won his only previous encounter with Kucera at Wimbledon in 1996.
Korda, who beat Sampras in last year's U.S. Open, outlasted No. 4 Jonas Bjorkman 3-6, 5-7, 6-3, 6-4, 6-2.
The three-hour match was the second consecutive Grand Slam quarterfinal meeting between Korda and Bjorkman. In the U.S. Open, Korda retired in mid-match. He said he was so sick that starting the match was a mistake.
In women's play, Lindsay Davenport outslugging 17-year-old Venus Williams, advancing to her second consecutive Grand Slam semifinal with a 1-6, 7-5, 6-3 victory.
Davenport, who conceded that after the first set "I thought I was down and out," added: "I fought hard because I wanted to maybe show people that I am a No. 2 seed and I am a pretty dangerous player."
In the semifinals, she will meet No. 8 Conchita Martinez, a 6-3, 6-2 winner against No. 9 Sandrine Testud.
Williams, a finalist in last year's U.S. Open, didn't offer much explanation for what went wrong after one set of "practically perfect tennis."
But she did make a vow after each player was broken seven times in the match: "I'm going to be holding more in the future. As a matter of fact, in the future I don't plan to be broken ever again."
She was, however, just hours later. In a battle of the sexes challenge raised by the Williams sisters, she played men's No. 203 Karsten Braasch of Germany and lost 6-2. She stepped in after 16-year-old Serena had lost 6-1.
Against Davenport, Williams yielded only nine points in the first set, but said, "It's not the easiest thing to keep up with such a game, especially in the second set. Your opponent is really going o want to say, 'Hey, I can't get run through like this.' "
But it was with a little help from Williams that Davenport took a 3-0 lead in the second set. Williams had two break points in the first game, a game point in the second, and three more break points in the third.
Davenport, often hesitant to go to the net, changed tactics to come in when she had a chance.
"I saved one of her game points coming into the net and hitting a volley, and it gave me a lot of confidence. ... Coming to the net helped my game get better because it helped me to step forward and move into the ball," she said.
Mostly, however, it was a baseline battle of two heavy hitters, winner or error.
The No. 16-ranked Williams said today's lesson was that "I have to capitalize on my opportunities. It's just like life. You let them pass by, you don't get them again, and I had too many in that match."
But, she said, "I can't be so very unhappy because this is my fourth Grand Slam. Most people don't even have four Slams."
Davenport, making her 23rd Grand Slam appearance at age 21, has yet to reach a final, although she has an Olympic gold medal.
She didn't set out specifically Tuesday to end Williams' run and curb the hype, she said, "but I didn't want to lose to her."
The Williams sisters have talked about becoming Nos. 1 and 2. Venus slowed Serena's rise through the rankings -- she now is No. 53 -- by beating her in the second round. Defending champion Martina Hingis fended off a challenge from 16-year-old Russian Anna Kournikova, No. 29, in the third round.
Croatian 15-year-old Mirjana Lucic, No. 47, suffered no disgrace in losing in the second round to French Open champion Iva Majoli.
Davenport said she has not been jealous of the attention given the Williams sisters.
"For a long time, women's tennis has gotten really pushed into the background, and they have generated a ton of attention, as well as Kournikova and even Hingis. We consider her old now, but she is only 17," she said.
Korda said he had problems with his timing and "I started really bad today. Luckily I came back and won the match in five sets because last time when we met ... I had to retire and a lot of people punished me after that. Everybody said I didn't want to fight.
"I think Jonas is one of the fittest guys on the tour, and it means a lot to me. ... I'm proud of my work today," he added.
The Czech left-hander, who turned 30 last Friday, said, "It's fantastic at my age to come back to the top 10. It's like a dream coming true."
After he rose to No. 5 in 1992, injuries helped drag him down to No. 41 at the end of 1995. Back then, he said, "nobody would put a penny on me."
"If I could win a Slam, it would be a fantastic achievement for me," he said.
Still, he added, "I went from the bottom of the river to the high mountains again. I don't think I'd complain if I never win a Slam."