Top seeds ease through

Novak Djokovic and Rafael Nadal eased closer to a French Open quarterfinal showdown Tuesday while two-time champion Serena Williams blitzed her way into the second round.

But there were opening defeats for women's tour poster girl Eugenie Bouchard, the sixth seed, as well as men's 10th-seeded Grigor Dimitrov.

Top seed Djokovic, bidding to win a first French Open and become just the eighth man to complete the career Grand Slam, defeated experienced Jarkko Nieminen 6-2, 7-5, 6-2.

The victory over the 33-year-old Finn, who was playing in his 50th major, was Djokovic's 23rd consecutive win this year.

Nadal opened his bid for a 10th title with a 6-3, 6-3, 6-4 win over world number 296 Quentin Halys.

Women's top seed and world number one Serena Williams won 6-2, 6-3 in just 59 minutes against Czech qualifier Andrea Hlavackova.

Canadian sixth seed Bouchard, a semi-finalist in 2014, crashed out at the hands of France's Kristina Mladenovic.

Bouchard went down 6-4, 6-4 to the world number 44, her eighth defeat in her last nine matches.

Mladenovic, 22, goes on to face Danka Kovinic of Montenegro..

Also going out was Bulgarian 10th seed Dimitrov who suffered his second successive first-round exit in Paris, losing 7-6 (9/7), 6-2, 6-3 to Jack Sock of the United States.

Wimbledon champion and fourth seed Petra Kvitova needed two and a half hours to see off New Zealand's world number 80 Marina Erakovic 6-4, 3-6, 6-4, getting broken six times and committing 47 unforced errors.

The 25-year-old goes on to face Silvia Soler-Espinosa of Spain.

Spain's David Ferrer won his 300th claycourt match when he swept past Slovakia's Lukas Lacko, 6-1, 6-3, 6-1.

Croatia's Marin Cilic, the ninth-seeded US Open champion, defeated Robin Haase of the Netherlands 6-2, 6-4, 6-2.

Svetlana Kuznetsova, the 2009 champion, beat Dutchwoman Kiki Bertens 6-1, 4-6, 6-2 and will next face 2010 winner Francesca Schiavone of Italy.