PARIS — Amelie Mauresmo defeated Jelena Jankovic 6-2, 0-6, 6-1 Saturday in the Open GDF Suez semifinals to set up a meeting with Elena Dementieva, who advanced after top-ranked Serena Williams withdrew with a knee injury.

Williams said she hurt the knee during Friday's win against Emilie Loit and was in too much pain to play.

"My left knee always hurts, but this time it's my right knee," Williams said. "When I woke up this morning, it wasn't feeling good. I wasn't moving well at all in practice.

"Today I don't feel like I could have gotten there. I wanted to make the fans extremely happy. It wouldn't have been a good showing for me at all."

Jankovic wasted three break points at 1-1 in the last set before Mauresmo seized her chance in the next game, hitting a cross-court forehand winner for a 3-1 lead. Mauresmo converted her third match point on a backhand from Jankovic that went long.

In the opening set, Mauresmo broke Jankovic's serve for a 3-1 lead and saved a break point at 4-2 with a forehand that caught the tape. Jankovic sent a forehand long to hand Mauresmo the set.

But the third-ranked Serb won the next six games to clinch the second set.

Dementieva was looking forward to playing Williams in the semifinal.

"It's just unfortunate we couldn't play," Dementieva said. "I feel sorry for her. This is not the way you want to be in the final."

Williams, who won the event in 1999 and 2003, said her injury may be the result of too much court time. She won the Australian Open last month.

"I've been playing a lot of tennis. Maybe it's just a sign that I need to take a day off or two and get ready for the next event," said Williams, who is set to play in the Dubai Championships next week.

"I'm gonna make the effort to play and be there. I just think I'll be OK. I just have to make sure it stays strong."