Top seeds Novak Djokovic and Serena Williams both swept into the last 16 at the French Open on a rain-hit Saturday in Paris, while Dominic Thiem confirmed his status as an outsider to win the men's title.

French hopes of a first home win in 33 years, meanwhile, were dealt a heavy blow when sixth-seed Jo-Wilfried Tsonga retired with a groin injury in the first set of his match with Ernests Gulbis.

Djokovic, who can become just the eighth man to win all four Grand Slam tournaments should be emerge triumphant next weekend, beat Britain's Aljaz Bedene 6-2, 6-3, 6-3 just before the light became too poor to play in.

The Serb, winner of the last three Grand Slam tournaments, has seen his chances of adding the French title considerably improved by the shock injury withdrawal of nine-time champion Rafael Nadal.

Williams, seeking an Open-era, record-equalling 22nd Grand Slam title, was a set up and about to tackle a second set tie-break against France's Kristina Mladenovic when a thunderstorm sent everyone scurrying for cover.

On the resumption, more than two and a half hours later, the top seed and defending champion needed five match points to finish the job going through 6-4, 7-6 (12/10) with Ukraine 18th seed Elina Svitolina next in her line of fire following her victory over former champion Ana Ivanovic.