Andy Murray advanced past Paul-Henri Mathieu with a 7-5 6-3 victory in the second round at the BNP Paribas Open in Paris.
The US Open champion overpowered his 30-year-old French rival in one hour 33 minutes.
Mathieu, a wildcard entrant, pushed Murray throughout the opening set, but succumbed thereafter before conceding the match with a double fault.
"I felt okay. I served pretty well, but I struggled a bit on the return especially at the beginning of the match," Murray told Sky Sports 2.
"It's hard to say (how long it will take to return to full match sharpness). I've been playing very well in practice and felt confident today, but when the match started it's different conditions.
"I struggled with my timing. I've never played my best tennis at this tournament, but I'd like to change that. You'd hope after three or four matches you are starting to play better."
Murray will next meet qualifier Jerzy Janowicz, who he beat in the Davis Cup a couple of years ago, after the Pole upset 13th seed Marin Cilic on Tuesday.