Novak Djokovic opened his French Open campaign with a comfortable 6-3, 6-4, 6-4 victory over Brazilian Rogerio Dutra Silva on Monday. The 12-time Grand Slam winner was well below his best on Court Philippe Chatrier, though, and dropped serve three times against the world number 134 Dutra Silva. In the women's singles draw, second seed Caroline Wozniacki held off the challenge of American Danielle Collins to ease through their French Open first-round match 7-6 (7/2), 6-1 on Monday.
Djokovic, whose form has been steadily improving since returning from a right elbow injury earlier this year, was still far too good for his opponent and will next play either David Ferrer or qualifier Jaume Munar.
"It was good to start this year with a win. I wasn't at my best, he played with a lot of spin. I didn't play very well, but I won in three sets," said the 31-year-old.
The Serbian has not won a major title since completing the career Grand Slam at Roland Garros in 2016, and lost in last year's quarter-finals to Dominic Thiem.
Wozniacki, the Australian Open champion, has never reached the semi-finals at Roland Garros, but after a tight first set, she was too strong for surprise Miami semi-finalist Collins, who was making her French Open debut.
The 27-year-old Dane will take over from Simona Halep as world number one if she lifts the title a week on Saturday.
Wozniacki will next face Spanish qualifier and world number 219 Georgina Garcia Perez for a place in the last 32.
Meanwhile, former French Open champion Stan Wawrinka continued to struggle with form and fitness as he was dumped out in the first round by Guillermo Garcia-Lopez on Monday, a defeat which will send his world ranking plummeting,
Wawrinka, who lost to Rafael Nadal in last year's final and won the 2015 title, was beaten in a five-set thriller 6-2, 3-6, 4-6, 7-6 (7/5), 6-3 by the Spanish world number 67 on Court Suzanne Lenglen.
The 33-year-old has been plagued by a knee injury and arrived at Roland Garros having won just one match on clay in Geneva last week, his first event in three months.