Serena Williams today moved into the second round of the Olympic tennis tournament with a comfortable win over Olga Govortsova, from Belarus.

Williams, the No4 seed, took just one hour and 19 minutes to win in straight sets, 6-3, 6-1.

The eight-time Grand Slam champion, a doubles gold medallist in Sydney eight years ago with sister Venus, was making her debut in Olympic singles after missing Athens with a knee injury.

She led the 47th-ranked Govortsova 6-3, 2-1, when heavy rain forced all action to be cancelled on Sunday.

In earlier first-round matches, Denmark's Caroline Wozniacki beat Selima Sfar of Tunisia 6-4, 6-1 and Australian Samantha Stosur overcame Sara Errani of Italy 6-3, 6-2.

Bulgarian Tsvetana Pironkova went through to the second round with a 6-3, 6-4 victory over Poland's Marta Domachowska, while Italy's Francesca Schiavone was a 6-4, 6-2 winner over Uzbek Akgul Amanmuradova.