His family may have expanded but it was business as usual for Roger Federer as he led the first-round winners on the opening day of play at the French Open.

It is less than three weeks since Federer went from a father of two to a father of four as wife Mirka gave birth to a second set of twins, Leo and Lenny.

All the family have travelled with him to Paris and his four-year-old daughters, Charlene and Myla, were in his box on Court Philippe Chatrier for the start of his 6-2 6-4 6-2 win against Slovakian Lukas Lacko.

Federer lost his first match since the birth of his sons in Rome to Frenchman Jeremy Chardy but was never troubled on Sunday, perhaps not surprisingly given Lacko has not won a match on clay for three years.

He had not even contested a match on the surface since Roland Garros last year and was forced to fight hard for the games he did win.

Lacko saved six of the 11 break points he faced but did not create a single one on the Federer serve, winning just nine points on the fourth seed's serve in the one hour and 24-minute match.

As could be expected, Federer, who extends his record by playing in a 58th consecutive grand slam tournament, was in a very positive mood after the match.

The Swiss said: "Everything is great.

"I'm happy I got off to a good start for the tournament here in Paris. There's always that little bit of a feeling that if you don't feel well, if the opponent plays great, whatever happens, you could lose early.

"So I was happy getting early signs out of the match that I was actually playing well and I was going to get my chances I was looking for. I'm very pleased with the outcome of the match.

"My personal life, as we know, it's all great, so I'm happy the family is here."

"Rafa is the favourite, and then Novak, and then the rest. It's very clear." - Roger Federer  

Federer, meanwhile, does not agree with the betting market that makes Novak Djokovic the favourite for the title ahead of Rafael Nadal.

On Nadal, the Swiss said: "I think he's back where he wants to be. He's played the matches he needs to play.

"Three weeks ago (Djokovic) couldn't play tennis any more, I remember that too. When he was injured, oh my God, things are looking so terrible. Now everything is great.

"Rafa is the favourite, and then Novak, and then the rest. It's very clear."

Home hope Jo-Wilfried Tsonga, who defeated Federer in the quarter-finals last year, opened his campaign with a 7-6 (7/4) 7-5 6-1 victory over countryman Edouard Roger-Vasselin.

Sixth seed Tomas Berdych, sporting an eye-catching floral shirt, made smooth progress through to the second round with a 6-3 6-4 6-4 win over Peter Polansky of Canada.

The Czech has worn a range of striking clothing since changing his sponsor, including a striped blue and white shirt at the Australian Open.

Berdych said: "You can find everything with flowers for the summer, so I was just really convinced in the first second. It's really nice. It's very different."

One of the most intriguing first-round match-ups pitted eighth seed Milos Raonic against 19-year-old Australian wild card Nick Kyrgios.

The teenager looks set to have a bright future but he found Raonic too tough, the Canadian winning 6-3 7-6 (7/1) 6-3.

Twenty-second seed Jerzy Janowicz broke a nine-match losing streak stretching back to February with a 6-1 6-4 6-7 (6/8) 6-4 victory over Victor Estrella Burgos.

Estrella Burgos, a 33-year-old from the Dominican Republic, was making his first appearance in the main draw of a grand slam.

Tenth seed John Isner prevailed in three tight sets against Pierre-Hugues Herbert and could play fellow marathon man Nicolas Mahut in round two.

Mikhail Youzhny and Radek Stepanek both recovered from two sets down and will face each other in the second round.

Eight-time champion Nadal begins his campaign on Monday, rather surprisingly not on Chatrier but on Roland Garros' second court, Suzanne Lenglen, where he will play US wild card Robby Ginepri.

Djokovic and Australian Open champion Stan Wawrinka are on Chatrier, against Portugal's Joao Sousa and Guillermo Garcia-Lopez, respectively.