Jiri Novak recovered from a shaky start to beat Spaniard Albert Montanes 3-6 6-3 6-3 in the second round of the Swiss Open on Wednesday. Novak was outplayed by clay-court specialist Montanes in the opening set before he took control to complete his 12th straight victory in the event.
The fourth-seeded Czech won the Gstaad title in 2001 and 2003.
"I struggled in the first set but was more aggressive in the second," he said. "In the third, I was focused."
The defending champion will play Potito Starace in the quarter-finals after the unseeded Italian beat Romanian Victor Hanescu 3-6 7-6 7-6.
In other maches, Russia's Igor Andreev upset eighth seed Albert Costa, beating the Spaniard 6-2 6-4.
But another Spanish plyayer, Ruben Ramirez Hidalgo, came through against Austria's Stefan Koubek, winning 6-3 6-4, and he will play Andreev.