The defending champion and top seed posted comfortable straight-sets wins to reach the quarterfinals as upsets claimed four of the tournament's top eight seeds.

Ferrer beat Oscar Hernandez of Spain 6-1, 6-2 in his first round match and returned to the court to beat Sergio Roitman of Argentina 6-1, 7-6 (2) in the second.

"I served very well and I'm happy with my game," Ferrer said. "I'm pleased I won two matches. The results make it look easy, but not the games."

Ferrer's quarterfinal opponent Thursday will be Julien Benneteau of France who beat sixth seed Nicolas Almagro of Spain 6-4, 2-6, 6-2 in his second-round match.

Florian Mayer mixed powerful groundstrokes, deft drop shots and occasional forays to the net to upset second seed Juan Ignacio Chela 6-3, 7-6 (7).

Mayer missed an early chance to serve out the match but fought back in the second set tiebreak to beat his top-20 ranked opponent.

"I got a little bit tired near the end," Mayer said. "It's not normal that you get 6-3 and you're serving for the match against a top-20 player. I'm very happy I could beat this guy.

"I'm ranked outside the top 50 and it feels good to beat a guy like that. If you want to beat him you have to destroy the rhythm of his game and I managed to do that."

Xavier Malisse of Belgium beat the fifth seed and 2006 champion, Jarkko Nieminen of Finland, 7-6 (3), 6-3 in his first round match Wednesday but lost 6-4, 6-4 to qualifier Nicolas Massu in the second round.

Massu faces fourth seed and former French Open champion Juan Carlos Ferrero of Spain in the quarterfinals. Ferrero beat Jesse Levine of the United States 6-4, 6-1 and Jurgen Melzer of Austria 6-3, 7-6 (8) in his two matches Wednesday.

Third seed Juan Monaco of Argentina won two matches Wednesday, beating former Australian Open champion Thomas Johansson of Sweden 6-3, 6-4 and 2006 finalist Olivier Rochus of Belgium 6-3, 6-3.