Serena Williams outclasses Vera Zvonereva to reach Olympic quarters

Wimbledon champion Serena Williams has blasted her way into the quarter-finals of the Olympic women's singles by beating Vera Zvonereva in under an hour.

Russian Zvonereva got off to the worst possible start by losing her serve to-15 under the Centre Court roof before Williams raced to the opening set 6-1 with two further breaks.

The American didn't let up in the second and continued a run of successive games against the 13th seed, eventually racking up 10 in a row to take the second set to-love and seal the match in just 52 minutes.

Williams will take on either Slovakia's Daniela Hantuchova or Caroline Wozniacki of Denmark in the last eight at the Games.