Gilles Simon has saved six of seven break points to advance to the second round of the Monte Carlo Masters.
The 15th-seeded Frenchman beat Viktor Troicki 6-3 6-4 on Sunday, improving his career record against the Serb to 6-0.
Simon next plays Grigor Dimitrov of Bulgaria or Filip Krajinovic of Serbia.
Jeremy Chardy of France had eight aces against Russian Andrey Kuznetsov, winning 7-6 (7-3) 7-5 in a topsy-turvy encounter featuring nine breaks of serve.
Top-ranked Novak Djokovic, a two-time winner in Monaco, begins his title defence against either Czech Jiri Vesely or Russian Teymuraz Gabashvili.
The Serb, who has a first-round bye, is in the same half of the draw as third-seeded Roger Federer.