Serena Williams of the United States completed a "career Golden Slam" at the London 2012 Games on Saturday, adding the Olympic women's singles tennis gold medal to her four tennis major titles.

Williams, playing in her third Olympics, dominated Russian Maria Sharapova 6-0, 6-1 to continue a 17-match winning streak. Sharapova was playing in her first Games.

Williams, who had previously twice won gold in doubles, claimed the singles gold on the same day twin American brothers Mike and Bob Bryan won the gold medal in men's doubles. Fellow Frenchmen Julien Benneteau and Richard Gasquet took bronze.

Williams will also seek a third gold in doubles with her sister, Venus Williams. They were set to play Russians Maria Kirilenko and Nadia Petrova on Saturday.

Also in tennis, the Team GB duo of Andy Murray and Laura Robson won through to the semifinals of the mixed doubles, also to be played Saturday, a day after Murray defeated Novak Djokovic to earn a place in the men's final Sunday against Roger Federer.