* Federer and Serena enjoy easy wins
* Home favourite Simon survives five-set thriller against Hewitt
* Petrova and Venus become first seeded casualties (Adds Venus Williams loss)
PARIS, May 26 (Reuters) - Roger Federer is used to ending grand slam tournaments on Sundays rather than starting them but the French Open's quirky schedule could not throw the Swiss stylist off his stride as he strolled through his Roland Garros opener in ruthless fashion.
The 31-year-old had his nose put out of joint when forced to play on opening Sunday when the French Open brought forward the start in 2006 but he was serene as he thrashed Spanish grand slam rookie Pablo Carreno-Busta 6-2 6-2 6-3 in the first round this year.
He was in good company too.
Federer, winner of a record 17 grand slam titles, walked out on a chilly Philippe Chatrier court after 15-times major winner Serena Williams put down an early marker with a 51-minute drubbing of Georgia's Anna Tatishvili.
American Williams turned her match against Tatishvili into little more than a practice session, winning 6-0 6-1 before completing the tougher task of conducting a courtside interview in French.
"It's way, way, more nerve-racking than playing tennis," Williams said after a charm-offensive that went down well with the Parisian crowds wrapped up under coats in the stands.
Federer, who often does his post-match news conferences in three languages, was equally impressive on the opening day alongside the Bois de Boulogne.
The Swiss former champion, seeded two and with a realistic chance of reaching the final after being placed in the opposite half of the draw to his Roland Garros nemesis Rafa Nadal and world number one Novak Djokovic, sealed victory with a graceful backhand winner.
"It's clearly important to win in straight sets if you can and not waste extra energy," Federer told reporters.
"I put a lot of focus on that always, especially in the early rounds of a tournament."
Serbian Ana Ivanovic, a third former French Open champion scheduled to brighten up the day's 32-match schedule, had to work a little harder to reach the second round.
The 2008 champion, who has never hit those heights again, got past Croatia's Petra Martic 6-1 3-6 6-3.
Gilles Simon, one of six Frenchmen seeded as the host nation desperately craves a first male champion since Yannick Noah in 1983, gave fans on Suzanne Lenglen anxiety attacks as he lost the opening two sets to old warrior Lleyton Hewitt before recovering to win 3-6 1-6 6-4 6-1 7-5.
Simon led 5-0 in the fifth set but an attack of nerves almost let veteran Aussie Hewitt steal victory.
"I'm just sad that it takes me one hour to feel good on the court," Simon told reporters. "Today I got lucky."
David Ferrer, seeded fourth after the withdrawal of Briton's Andy Murray, eased into the second round with a 6-4 6-3 6-4 defeat of another Australian, Marinko Matosevic, who has now lost his last nine grand slam first rounds.
Two women's seeds fell, most notably fading force Venus Williams who suffered only her fifth first round defeat in 59 grand slam tournaments when she was dispatched 7-6 6-7 6-4 by Poland's Urszula Radwanska with darkness falling.
Women's 11th seed Nadia Petrova of Russia was the day's highest-ranked casualty, losing to Puerto Rican teenager Monica Puig 3-6 7-5 6-4 but last year's runner-up Sara Errani was untroubled beating Arantxa Rus 6-1 6-2.
Federer, who in 2006 made his feelings known to organisers after being served up as a tasty tournament appetiser for a Sunday first round against Diego Hartfield, was far more relaxed this time round after again being asked to showcase the tournament's unique Sunday start.
Up against a young Spaniard who won seven consecutive titles at the third-tier Futures level of the men's tour this season, Federer warmed to the task immediately.
"I remember they sort of forced me to play on Sunday years back to promote their Sunday thing," Federer told reporters.
"Wimbledon does it in 13 days and the French does it in 15. So it doesn't make sense. But I do understand that a weekend for tennis is very important for the people who can show up.
"But I'm happy this time around. I told them if they wanted me to play Sunday, whatever, I'm fine with it. They took that opportunity right away."
Looking confident and razor-sharp on the back of a 24-match winning streak, 2002 champion Serena Williams took the first set against Tatishvili in 20 minutes, striking winners with ominous ease.
"I have to say I'm always a little nervous going into first round matches at slams, but this time I wasn't as nervous as I was previously," said the 31-year-old, who has been almost unbeatable since a shock defeat by Virginie Razzano in the first round here last year.
"I felt pretty safe and felt good about my game and that if I can just do what I do in practice, I'll be okay."
As is the way when Serena wins easily, post-match questions quickly moved away from her tennis.
As well as her linguistic skills, the American also expressed her delight at attending an art class in Paris.
"I'm good at that," she said when asked if she has done a self-portrait. "I just draw a circle with a line and then two arms, and then I just draw a lot of hair and a stick figure.
"I'm telling you, I'm a terrible artist." (Editing by Pritha Sarkar)