Top-seeded Juan Martin del Potro of Argentina eased past Marcos Baghdatis of Cyprus 6-1, 6-2 in the Swiss Indoors second round on Thursday.
Del Potro forced two breaks of serve in each set and saved all five chances the 97th-ranked Baghdatis held in the first set.
In Friday's quarterfinals, del Potro will face Paul-Henri Mathieu of France, who beat compatriot Michael Llodra 6-4, 6-3.
Five-time Basel champion Roger Federer is in the other half of the draw, and faces the winner of Thursday's late match between eighth-seeded Grigor Dimitrov of Bulgaria and Alexandr Dolgopolov of Ukraine.
Also, Vasek Pospisil of Canada overcame big-serving Croat Ivo Karlovic 6-3, 6-4, and Edouard Roger-Vasselin of France and Daniel Brands of Germany also won.