Roger Federer began the defence of his French Open title with a comfortable victory over world number 71 Peter Luczak.
The Swiss star was rarely troubled in a 6-4 6-1 6-2 victory on court Philippe Chatrier that sets up a second-round match with Colombia's Alejandro Falla.
World number one Federer hailed the match as the "perfect" opener to what he hopes will be a two-week stay at Roland Garros.
Novak Djokovic survived a second-set wobble to book his place in the second round with a four-set victory over Evgeny Korolev.
The third seed and former Australian Open champion won 6-1 3-6 6-1 6-3 on Suzanne Lenglen Court to set up a meeting with either Kei Nishikori or Santiago Giraldo.
Djokovic looked like steamrollering his opponent after racing to a set and a break lead, but the Serbian lost six of the next seven games as Korolev - a cousin of Anna Kournikova - went for broke, especially on his forehand.
That was as good as it got for the world number 73 as Djokovic regained his stranglehold.
Feliciano Lopez became the second seeded casualty in the men's draw when the famously clay-shy Spaniard was dumped out 6-1 7-6 (7/5) 6-2 by Julian Reister.
Otherwise, the day belonged to Slovakia's Lukas Lacko, who finally saw off American Michael Yani in a match carried over from on Sunday. At four hours and 56 minutes, the contest was the joint longest in the Open era at Roland Garros, Lacko winning 4-6 7-6 (7/5) 7-6 (7/4) 6-7 (5/7) 12-10.
Among the seeds safely through by mid-afternoon were Tomas Berdych (15), who beat Jorge Aguilar 7-6 (9/7) 6-3 6-1, John Isner (17), who saw off Andrey Golubev 6-4 6-3 6-2, Stanislas Wawrinka (20), who got past Jan Hajek 6-1 6-3 6-3, and Marcos Baghdatis (25), who was a 6-3 6-4 6-3 winner against Jesse Witten.