Clay isn't known as Roger Federer's surface, but he's the only top 5 ATP member still standing on the blue dirt in Madrid.
He is joined in the semifinal round by world No. 8 Janko Tipsarevic, along with world No. 7 Tomas Berdych and world No. 11 Juan Martin Del Potro.
Tipsarevic defeated world No. 1 and the tournament's defending champion Novak Djokovic in the quarterfinal round.
On the women's side, eight women remain. World No. 1 Victoria Azarenka survived a scare from 2011 French Open champion Li Na. Azarenka pulled through in three sets.
Her next match, which will be against world No. 3 Agnieszka Radwanska is tilted heavily in Azarenka's favor. She has won the last four meetings. However, the only games Radwanska has dropped this season have been in her matches against Azarenka.
Then there's swinging' Serena Williams, who is looking to return to her consistent final-round appearances. Williams will face the Czech Republic's Lucia Hradecka. Hradecka disposed of both Petra Kvitova and Sam Stosur.
We'll see if Federer or any of the other top players are quoting Djokovic on Day 7.
From the AP:
"I want to forget this week as soon as possible and move on to the real clay courts," Djokovic said. "Here you can't predict the ball bounce or movement.They can do whatever they want, but I won't be here next year if this clay stays."