Top seed Roger Federer had no such difficulties against Spaniard Marcel Granollers, winning 6-3, 6-4 with a flurry of spectacular winners to reach the quarterfinals.
Eighth-seeded Latvian Ernests Gulbis lost 6-3, 5-7, 6-1 to Sergiy Stakhovsky of Ukraine and third seed Czech Tomas Berdych defeated Russia's Nikolay Davydenko 6-3, 7-6.
Also through to the last eight are Richard Gasquet, a 6-2, 7-5 winner over Sergei Bubka, Florian Mayer, who dismissed Andrey Golubev 6-3, 6-4, Gilles Simon, who defeated Lukas Rosol 6-2, 6-3, and Philipp Petzschner, who beat Philipp Kohlschreiber 6-0, 4-6, 6-2.
World number one Caroline Wozniacki moved into the quarterfinals with a 6-3, 6-2 win over Russian Nadia Petrova but third seed Francesca Schiavone was upset by China's Peng Shuai on Wednesday. Second seed Vera Zvonareva also secured a spot in the last eight with a 6-1, 6-2 win over Slovakia's Dominika Cibulkova.
French Open champions Schiavone had a less memorable day with Chinese qualifier Peng in top form on her way to a 7-5, 6-3 victory. France's Marion Bartoli eased past Israel's Shahar Peer 6-1, 6-0.