Rafael Nadal won his 58th consecutive match on clay and cruised into the semifinals of the French Open on Wednesday when Novak Djokovic retired down 4-6, 4-6 with a back injury.
The defending champion's semifinal opponent on Friday will be fourth-seeded Croat Ivan Ljubicic, who disposed of Frenchman Julien Benneteau 6-2, 6-3, 6-2 in another quarterfinal.
For the first time since 1985, the top-four players in the world have reached the semifinals at a Grand Slam event. The last time occurred at the '85 French Open (John McEnroe, Ivan Lendl, Mats Wilander, Jimmy Connors).
In the second set, Djokovic took a medical timeout after being broken to 0-3 and laid on the court while being stretched out by the trainer.
The 19-year-old Serb made a strident effort to push at Nadal after that and came up with some tremendous forehands and deep backhands, but the Spaniard staved off the challenge and held to win the second set 6-4.
Djokovic retired in the opening game of the third set.
"It's not nice to win like that," said Nadal. "I'm sorry for him.But this is good for me to head to the semifinals."
The 27-year-old Ljubicic ended the impressive run of Benneteau at the French Open as he uncorked 13 aces and broke Benneteau's serve eight times.
This is Ljubicic's best-ever showing at a Grand Slam event, with his previous-best effort being a trip to the quarterfinals at this year's Australian Open.
China's fourth seed Zheng Jie and Yan Zi rallied to beat Russian duo Anna Chakvetadze and Elena Vesnina 4-6, 6-2, 6-1 to reach the women's doubles semifinals.
Zheng/Yan, who claimed China's first ever grand slam title when they won the doubles crown in this year's Australian Open, will next take on Daniela Hantuchova of Slovakia and Ai Sugiyama of Japan.