As a kid, Nicole Vaidisova used a yellow Venus Williams-model racket, honing her game with the goal of someday beating the world's best players.
Such as Williams.
And that's what the 17-year-old Vaidisova did on Tuesday, staging a comeback for her second successive upset at the French Open. She beat Williams 6-7 (5), 6-1, 6-3 to earn her first Grand Slam semifinal berth against Svetlana Kuznetsova on Thursday.
"She played really good tennis and seems to be on a roll," Williams said.
In her previous match, the precocious Czech beat top-ranked Amelie Mauresmo by a similar score: 6-7 (5), 6-1, 6-2.
"I've surprised myself a little," Vaidisova said.
Williams again came up short in her 10th try for a Roland Garros title.
"I would have loved to have done better," she said.
Earning berths in the other semifinal were Belgians Justine Henin-Hardenne and Kim Clijsters, who will play each other for the 18th time on Thursday. Henin-Hardenne, who won the tournament in 2003 and 2005, beat Anna-Lena Groenefeld of Germany 7-5, 6-2. Clijsters defeated Martina Hingis 7-6 (5), 6-1.
On the men's side, top-ranked Roger Federer moved closer to his fourth consecutive Grand Slam title by beating Mario Ancic of Croatia 6-4, 6-3, 6-4. Roland Garros is the only major event Federer has yet to win.
"I'm much more relaxed now," he said. "There was enormous pressure at the start of the tournament."
His opponent on Friday will be No. 3-seeded David Nalbandian of Argentina, who beat Nikolay Davydenko of Russia 6-3, 6-3, 2-6, 6-4.