Top-seeded Juan Martin del Potro of Argentina breezed into the Mifel Open semifinals Thursday night, beating Egor Gerasimov of Belarus 6-1, 6-1.
Del Potro won for the second straight night in the hard-court event after a rest break following a five-set loss to Rafael Nadal in the Wimbledon quarterfinals.
Del Potro has 22 career victories, winning this year on hard courts at Indian Wells and Acapulco.
In the semifinals, the 2009 U.S. Open champion will face third-seeded Damir Dzumhur of Bosnia and Herzegovina in the semifinals. Dzumhur beat American Michael Mmoh 6-2, 6-3.
Dzumhur has three career victories, taking a grass-court tournament in June in Turkey after breaking through last year with indoor titles in Moscow and St. Petersburg.
Second-seeded Fabio Fognini of Italy will play British left-hander Cameron Norrie in the other semifinal. Fognini beat Japan's Yoshihito Nishioka 6-2, 6-2, and Norrie topped fourth-seeded Adrian Mannarino of France 6-4, 6-4.
The 31-year-old Fognini, ranked 15th in the world, is seeking his third victory of the year after winning clay-court tournaments in Bastad and Sao Paolo. Norrie also reached the semifinals last week in Atlanta.