Roger Federer fell well below his usual Sunday best in the French Open first round but France's Amelie Mauresmo showed no sign of any first-day nerves.
Top seed Federer, who is seeking to win the only Grand Slam title missing from his collection, trailed 3-0 and 5-3 in the first set against Argentine qualifier Diego Hartfield before securing a 7-5, 7-6, 6-2 victory.
The world number one is more used to winning finals on Sundays than contesting first round matches and he was unhappy at being made to play on the first Sunday start in the claycourt Grand Slam's history.
"I requested not to play Sunday, so I wasn't happy to play today," the Swiss said.
"I didn't want to be the guy who starts the tournament. I was never happy about that idea. I told everybody that I didn't want to play Sunday.
"I'm happy I didn't lose because otherwise I'd be very angry right now."
Roland Garros added a 15th day to its schedule with the aim of increasing television exposure, meaning the first round is being spread over three days instead of two.
Mauresmo, the world number one who has often wilted under the spotlight at her home event, was an impressive 6-4, 6-4 winner over American Meghann Shaughnessy in the match that followed Federer's.
The Australian Open champion, who has benefited from a favourable draw, appropriately sealed victory with an ace.
"It's satisfying for a first round, even if it was not the match of the century," she said.
Men's third seed David Nalbandian of Argentina swept through to round two with a 6-2, 7-6, 6-4 victory over Switzerland's Stanislas Wawrinka.
Federer has not played since his Rome Masters final defeat by Rafael Nadal two weeks ago and trailed 3-0 in the first set before eventually subduing an opponent playing his first match at tour level.
BLUSTERY WIND
He is seeking to become only the third man to hold all four Grand Slam title simultaneously by winning the claycourt event but was outplayed for long periods in blustery wind and occasional sunshine on centre court.
His drop shot working to great effect, Hartfield dominated the first set and served for it at 5-4 before Federer clawed back.
The 25-year-old Argentine, who replaced injured Frenchman Arnaud Clement in the draw, owes his ranking of 156 to good performances on the lesser Challenger circuit. He continued to trouble Federer in the second set before losing it 7-2 in the tiebreak.
Hartfield began to struggle physically in the third set and a relieved Federer wrapped up victory with a forehand winner after two hours 36 minutes.
Nadal was due to play Sweden's Robin Soderling in his first-round match on Monday. If he wins, he will break Guillermo Vilas's 1977 record of 53 consecutive wins on clay.
Another Spaniard, Tommy Robredo is a potential quarter-final opponent of Federer. On Sunday the seventh seed and Hamburg Masters winner eased past Czech player Tomas Zib 6-4, 6-2, 6-2 in his first-round match on Court Suzanne Lenglen.
Briton Tim Henman, the surprise 2004 semi-finalist, was a 6-3, 6-4, 4-6, 6-4 winner over Denmark's Kenneth Carlsen.
