French Open: Sunday 25 May to Sunday 8 June
Coverage: BBC TV, BBCi, Radio 5 Live and the BBC Sport website.
Nadal was on court for the third day running in Paris
Rafael Nadal finally got his French Open title defence under way with a win over Brazil's Thomaz Bellucci.
The world number two was on court for the third day running thanks to the Paris rain and made a slow start against 20-year-old qualifier Bellucci.
But the three-times champion came through 7-5 6-3 6-1.
World number three Novak Djokovic became the first man to reach the third round with a crushing 6-1 6-1 6-3 win over Spain's Miguel Angel Lopez Jaen.
Djokovic, who could meet Nadal in the semi-finals, was on court for only 80 minutes as he booked a meeting with Korean Hyung-Taik Lee or Wayne Odesnik of the United States.
"It's always good to have an easy match," said the Australian Open champion.
Nadal faces French wildcard Nicolas Devilder in the second round after a decent test in his opening win over Bellucci.
"The conditions were very bad and the wind was terrible," said Nadal.
It's good to get through in tough conditions out there
"I had to wait two days because of the rain and could only practise for 20 minutes so it's difficult to come on to the court and find a good rhythm."
Elsewhere, Australian Lleyton Hewitt returned from a six-week injury break to thrash France's Nicolas Mahut 6-4 6-2 6-4.
The former world number one is playing his first clay-court tournament of the season following a hip injury.
"I really stepped up when I needed to, especially on my return of serve," said the former world number one.
"It's good to get through in tough conditions out there."
Fifth seed David Ferrer is also safely into the second round after a 6-3 6-4 6-3 win over Belgium's Steve Darcis.
But 2003 champion Juan Carlos Ferrero was forced to retire from his first-round match due to a leg injury.
Tomas Berdych, the 11th seed, was the major casualty of the day as he lost a titanic battle with Frenchman Michael Llodra, going down 6-3 4-6 5-7 6-3 6-4.
The Spaniard, the 23rd seed, was leading Brazilian Marcos Daniel 7-6 2-2 when he decided he was unable to continue.
"I've suffered this pain for quite a while but it's a bit of a strange problem because scans and X-rays don't show anything," said Ferrero.
Ferrero's compatriot Ferrer will face 35-year-old Frenchman Fabrice Santoro in the second round.
Santoro, playing in his 63rd Grand Slam tournament, eased past Russia's Evgeny Korolev 7-6 (7-3) 6-1 6-4.
Marat Safin booked an all-Russian second-round meeting with fourth seed Nikolay Davydenko by completing a 6-7 6-1 6-3 6-2 win over Monaco's Jean-Rene Lisnard.
Safin had levelled the match at one set all when rain brought play to a premature end on Tuesday.
"(Davydenko's) playing his best tennis probably right now," said Safin. "He won Miami. He beat Nadal and some other great players there, so he's pretty solid.
"Has to be a very good day for me and not really good day for him, and then we have a chance to be even."