Closing out play on Court Philippe-Chatrier, recent US Open finalist Alexander Zverev recovered from a break down in the opening set before completing a 7-5, 6-2, 6-4 over Austrian Dennis Novak.
The German No.6 seed now awaits the winner of the first round match between American qualifier Michael Mmoh and Frenchman Pierre Hugues-Herbert.
"I didn't play any clay-court matches before this, so this is my first one and the conditions are not very easy, so I needed to get used to it," said Zverev on court. "But also Dennis is somebody that, on this surface, plays very well. He grew up with Dominic Thiem, so basically all they did was practice on the surface. So I'm happy to get the win and get through to the second round."
Over on Court 14, former US Open finalist Kei Nishikori squeezed past Britain's Dan Evans 1-6, 6-1, 7-6(3), 1-6, 6-4 in three hours and 49 minutes.
The Japanese star, who had a bout of coronavirus over the summer that ruled him out of the US Open, is a three-time quarter-finalist in the French capital and next plays Italian Stefano Travaglia.
No.21 seed John Isner eased past French wild card Elliot Benchetrit 6-4, 6-1, 6-3 while his fellow American Taylor Fritz, the No.27 seed, was taken the distance by Czech teen debutant Tomas Machac, avoiding an upset by the qualifier 7-5, 7-6(2), 1-6, 2-6, 6-3.