Roger beat ninth-seeded Juan Martin del Potro of Argentina 6-3, 6-3 today to reach the Madrid Masters semifinals, where he will face Andy Murray in a rematch of the U.S. Open final.

Roger used an effective slice serve on the fast indoor surface and was never broken. "The slice goes nicely on this court, I felt good using it to counter Juan Martin's height," our star said. Roger also played serve-and-volley, chip and charge returns and clean passing shots against his 20-year-old opponent. Del Potro served 12 aces, including 11 in the first set, but couldn't trouble Roger. "He started serving great, many aces," Roger said. "That's what makes him the good player he is. I had the ability to stay calm and use my slice well here in Madrid where conditions are very quick."

Roger, who missed last week's Stockholm Open due to fatigue, said he felt happy with his physical condition. "I don't know what would have happened if I'd gone to Stockholm, but I'm playing well here," he said.