Roger Federer racked up a record-equalling 59th career win at the French Open on Sunday while Serena and Venus Williams edged closer to a third-round sister showdown.
Federer kicked off his 16th consecutive Roland Garros with a 6-2, 6-4, 6-2 win over Slovakia's Lukas Lacko, his first victory since becoming a father of twins for the second time.
The 32-year-old Swiss, who won his only Paris title in 2009, was watched by wife Mirka and older twins Myla and Charlene but not three-week old Lenny and Leo.
Sunday's triumph was also his 59th at Roland Garros, tying eight-time champion Rafael Nadal as the tournament's all-time win specialist.
Federer was never troubled by Lacko, the world number 88 who has not won a claycourt match for three years.
He hit 40 winners and goes on to face Diego Schwartzman of Argentina for a place in the last 32.
"I'm happy I got off to a good start," said the 17-time major winner.
"There's always that little feeling that if you don't feel well, if the opponent plays great, whatever happens so you could lose early. So I was happy seeing early signs out of the match that I was actually playing well and I was going to get my chances."
Women's top seed Serena Williams, who won the 2013 title to add to her 2002 maiden triumph in the French capital, started her 13th Roland Garros with a 6-2, 6-1 win over French wildcard Alize Lim.
Three days after the close friends were snapping 'selfies' of themselves at the players' party at the Eiffel Tower, Williams fired 37 winners past Lim, the world 138, although a sloppy final game left her relying on a fifth match point to seal victory.
The win extended Williams' record in opening rounds of the majors to 54-1 -- her only blip being a first-round exit to Virginie Razzano in Paris three years ago.
"We train in the same facilities. We just kind of all get along. We go to dinner every now and then. So it's interesting. It's fun," said the American.
Williams will face Spain's Garbine Muguruza for a place in the third round where she could then play big sister Venus.
Venus, the 29th seed and 2002 runner-up, began her campaign with a 6-4, 6-1 win against Swiss 17-year-old Belinda Bencic who was two and a half years from being born when the American made her professional debut back in 1994.
It was Williams' second win over world number 81 Bencic, the 2013 junior champion, having defeated the teenager in Luxembourg in 2012.
"I think she has a great attitude, and it will take her a long way. Just doing everything better, serving, returning, just more experience helps a lot," said 33-year-old Venus, who is playing in her 17th French Open.
Venus next faces Anna Schmiedlova of Slovakia.
- Good day for veterans -
It was a good day for other veterans on the tour.
Russian 15th seed Mikhail Youzhny, 31, battled back to see off Spain's Pablo Carreno Busta, 3-6, 1-6, 6-3, 6-4, 6-0.
Czech 35-year-old Radek Stepanek beat Facundo Arguello of Argentina 6-7 (8/10), 3-6, 6-4, 6-3, 6-2 and Finland's Jarkko Nieminen, 32, also needed five sets to see off Michal Przysiezny of Poland, 6-7 (7/9), 6-4, 6-7 (3/7), 6-3, 6-4.
Czech sixth seed Tomas Berdych eased past Canada's Peter Polansky 6-3, 6-4, 6-4 on the back of 50 winners and 15 aces and next meets Kazakhstan's Aleksandr Nedovyesov.
Canadian eighth seed Milos Raonic unleashed 27 aces in his 6-3, 7-6 (7/1), 6-3 win over teenage Australian wildcard Nick Kyrgios.
French 13th seed Jo-Wilfried Tsonga, a semi-finalist in 2013, beat compatriot Edouard Roger-Vasselin, 7-6 (7/4), 7-5, 6-2.
Italy's Francesca Schiavone, the 2010 champion and 2011 runner-up, crashed out with the 33-year-old slumping to a 6-3, 6-3 defeat to Croatia's Ajla Tomljanovic.
Only one seeded player lost on Sunday with Romania's Monica Niculescu accounting for Estonia's 25th seed Kaia Kanepi 5-7, 6-3, 6-1.
Polish women's third seed Agnieszka Radwanska carved out a 6-3, 6-0 win over China's Zhang Shuai, the world number 34, in the day's opening match on Court Philippe Chatrier.