final three sets to win 4-6, 3-6, 6-1, 6-2, 6-2.
"After the first two sets, the next three sets maybe I play my best game on grass in my life," Nadal said.
Venus Williams had a much easier time Thursday, playing outstanding tennis to reach the semifinals by beating No. 5 Svetlana Kuznetsova 6-3, 6-4. Williams will next face French Open finalist Ana Ivanovic, who defeated No. 14 Nicole Vaidisova 4-6, 6-2, 7-5.
Ivanovic saved three match points and beginning with the last one, won 13 of 15 points. That sent her on her way to taking the match's last four games. It ended when Vaidisova double-faulted for the sixth time.
"I knew I could do it," Ivanovic said. "I knew I could make some good shots and be aggressive and move forward and put pressure."
Play was suspended for the day with four-time defending champion Roger Federer and No. 20 Juan Carlos Ferrero still in the first set of their quarterfinal. Federer was serving at deuce at 5-5.
No. 3 Andy Roddick and No. 12 Richard Gasquet took the court to warm up but never started.
Youzhny, one of only three players to have beaten Nadal twice in the last year, struggled midway through his match with lower-back pain.
He called for a trainer after losing the third set. Lying on his stomach, the Russian got his back massaged. After the fifth game of the fourth set, he was again on the ground, with the trainer stretching his back.