Miami: Serena Williams of USA playing her first tournament after almost two months cruised into the last 16 of the Sony Ericsson Open played here on Saturday.

The former world number one Williams defeated Italy's Roberta Vinci 6-2 6-1 in a match that lasted for 67 minutes.

Williams won 70% of her first serve and broke her Italian opponent five times.

Williams would now face US Open Champion Samantha Stosur of Australia who defeated Chanelle Scheepers 2-6 7-5 6-2 from South Africa.

However the biggest shock of the day came when former World number one Kim Clijsters of Belgium was knocked out of the tournament by her compatriot Yanina Wickmayer. She lost 6-4 7-6 (7/5).

Other results:

Li Na (China) bt Iveta Benesova (Czech) 7-5 6-2.

Caroline Wozniacki (Den) bt Petra Cetkovska (Czech) 6-3 7-5,

Maria Sharapova (Rus) bt Sloane Stephens (US) 6-4 6-2.

By Indian Sports News Network