Mark Philippoussis found grass-court form to beat Belgian seventh seed Christophe Rochus 6-3 7-6 in the first round of the Ordina Open.
The Australian wrapped up victory on his third match point and will now play Spain's Guillermo Garcia-Lopez.
"I didn't feel great out there. I've been taking anti-inflammatories (for a back problem)," said Philippoussis.
"My serve got me out of trouble a lot, and to be honest I'm just glad to get off the court and get some rest."
Third seed Mario Ancic, a semi-finalist at Wimbledon last year, overpowered Dutch qualifier Paul Logtens 6-4 6-2.
But sixth seed Andrei Pavel was beaten 6-2 7-6 by Swede Jonas Bjorkman.