Britain's Katie Boulter finally landed her first French Open main-draw victory at the age of 28 after Jacob Fearnley won on his debut against former champion Stan Wawrinka.
Boulter, ranked 38th in the world, overcame a tense start to win 6-7 (4-7) 6-1 6-1 against French world number 231 Carole Monnet.
"I'm really pleased with myself," said Boulter, who could play reigning Australian Open champion Madison Keys in the second round.
"I sometimes find it really difficult on this surface and I've kind of persevered and tried my hardest to bring some good tennis.
"This one is special for me and it'll go in my books."
Also playing in front of a partisan opposition crowd, 55th-ranked Fearnley made smooth progress with a 7-6 (8-6) 6-3 6-2 victory over the popular 40-year-old Wawrinka.
The pair were joined in the second round by Emma Raducanu, who fought through "feeling sick" to China's Wang Xinyu earlier on Monday.
However, Jodie Burrage was unable to complete a British clean sweep on day two of the clay-court Grand Slam event.
The 25-year-old, playing under a protected injury ranking, lost 7-6 (7-1) 6-4 to American former world number seven Danielle Collins
