Janko Tipsarevic of Serbia eased into the Swiss Open semifinals by beating Czech qualifier Jan Hernych 6-2, 6-1 on Friday.
The top-seeded Tipsarevic is looking for his second straight clay-court title after winning last week at Stuttgart, Germany.
Tipsarevic next plays Frenchman Paul-Henri Mathieu, who rallied against Ernests Gulbis of Latvia to win 4-6, 6-1, 6-4.
The 30-year-old Mathieu, ranked No. 172 after recovering from a serious knee injury, will play his first semifinal on tour since September 2009. That was an indoor hard-court event in Metz, France.
Thomaz Bellucci, the 2009 Gstaad champion from Brazil, eliminated fifth-seeded Feliciano Lopez 6-3, 6-3. The Spaniard was called up for the London Olympics to replace the injured Rafael Nadal.
Grigor Dimitrov of Bulgaria beat Lukasz Kubot of Poland, 6-3, 6-2.