Despite a tough day serving, David Ferrer still won in straight sets.

THE ASSOCIATED PRESS

JOHANNESBURG, South Africa -- David Ferrer, smashing his racket in frustration with his serve, beat Swedish qualifier Filip Prpic 6-3, 6-4 Thursday to reach the SA Tennis Open quarterfinals.

The second-seeded Spaniard will next play India's Sondev Devvarman, who defeated Brazil's Thiago Alves 6-4, 6-1.

"I served badly in the second set," Ferrer said. "But to get through the match just before the rain came down was a relief. Prpic is a good player and a tough guy to beat and I had to fight hard out there."

Before rain halted the afternoon session, Devvarman got by Alves. The Brazilian needed a medical timeout because of the heat.

"I did feel for him," Devvarman said. "Although he started well by ripping some winners past me, he started to look sluggish as the game progressed. But I was very happy with my own game."

Also Thursday, it was top-seeded Gael Monfils against Josselin Ouanna, and South African wild card Raven Klaasen facing seventh-seeded Yen-Hsun Lu of Taiwan.