* Murray, Sharapova and Li Na progress, Ivanovic crashes out
Rafa Nadal had a severe fright before celebrating victory when he began the defence of his French Open title with a battling 6-4 6-7 6-7 6-2 6-4 win over John Isner on Tuesday.
The world number one was forced into his first five-set match at Roland Garros before finally outlasting the giant American, who quickly became a favourite among the fans despite Nadal's yearly exploits here.
"It's always a very, very close match with John," Nadal said at courtside. "I was there, I fought all the time. In the tiebreaks I was probably too nervous."
British fourth seed Andy Murray was broken twice in a 6-4 6-1 6-3 victory over Eric Prodon, a 29-year-old local qualifier who has won only one match on the main tour and was making just his fourth grand slam appearance.
Women's sixth seed Li Na, who like Murray was runner-up in January's Australian Open, started with an uninspiring 6-3 6-7 6-3 win over Czech Barbora Zahlavova Strycova as the day began with cloud.
In-form Maria Sharapova added the sunshine with a yellow dress as she routed Mirjana Lucic 6-3 6-0 and while Ana Ivanovic rivalled the Russian in the fashion stakes with a pink number, the tearful ex-champion lost 7-6 0-6 6-2 to Johanna Larsson.
Queues at the entrances to the famous courts in western Paris lengthened as temperatures warmed up and anticipation rose for Nadal's first match.
The Spaniard is seeking a sixth title in seven years but Australian Open champion Novak Djokovic, who easily won his first match, is threatening to break his dominance after a stunning unbeaten start to the year.
American Isner is best known for his 11-hour epic match against Nicolas Mahut at Wimbledon last year and he made Nadal sweat profusely with his high-bouncing serve and surprising deftness at the net.
He dominated the two tiebreaks, winning 7-2 in both as Nadal struggled to cope with Isner's all-round game and risked becoming the first French Open men's champion to go out in the first round.
Yet, using an inner-strength he has shown so often on other surfaces, "King of clay" Nadal dug deep to break twice, take the fourth set and steal most of the momentum.
Isner lost his way in the final set, dropping serve in the third game as Nadal closed out a testing tussle to set up a second-round meeting with compatriot Pablo Andujar.
Eighth seed Jurgen Melzer of Austria had no such difficulty seeing off German Andreas Beck 6-3 6-4 6-2.
Murray did not need to produce his best against the slightly rotund Prodon, who had a stomach bug but still broke in the first set with a drop shot.
The Scot, who next plays Italian Simone Bolelli, found more rhythm in the second but was broken again in the third set as Prodon's remarkably laidback but occasionally successful volleys and smashes amused the fans.
There were more laughs when organisers announced that American Ryan Harrison, who threw his racket into a tree when losing in qualifying last week, had won a lucky loser berth but he lost 6-1 6-7 6-3 7-5 to last year's runner-up Robin Soderling.
The feelings on Court Philippe Chatrier were completely different as France's Virginie Razzano, whose coach and fiance died eight days ago from a brain tumour, lost her match to Jarmila Gajdosova 6-3 6-1 to warm and heartfelt applause.
"I had a lot of emotion and pain," Razzano said tearfully. Number two women's seed Kim Clijsters returns from injury later against Anastasiya Yakimova.