Nadal batters Paire to begin title bid
"I'm very happy to be back here after what happened last year. It's great to feel the support," said the 14-time major champion.
Nadal dominated the opening set, then recovered from a slight second-set wobble when he dropped serve twice in a row to surge into a round two meeting with Dutchman Robin Haase.
The Spaniard, whose last Grand Slam triumph came at Roland Garros in 2014, improved his incredible French Open record to 73 wins and just two losses.
Nadal lost this year's Australian Open final in a five-set epic to Roger Federer, but the 30-year-old has marked himself out as the favourite on his preferred surface.
The fourth seed arrives in Paris with three clay-court titles to his name this season -- winning both Monte Carlo and Barcelona for a 10th time, while securing a fifth Madrid Masters crown.