The Spaniard, who is unbeaten at Roland Garros, will play world No148 Nicolas Devilder, of France, in the second round. Former champion Juan Carlos Ferrero's campaign ended when he quit with a leg injury while leading Brazilian Marcos Daniel 7-6, 2-2.
Lleyton Hewitt, the No25 seed, won 6-4, 6-2, 6-4 against Nicolas Mahut, of France, while fifth seed David Ferrer beat Belgium's Steve Darcis 6-3, 6-4, 6-3.
Mikhail Youzhny, the 15th seed, registered another win for Russia, beating Germany's Benjamin Becker 6-1, 6-3, 7-6.