Serena Williams of the U.S. serves over her sister, Venus Williams, to Czech Republic’s Hlavackova and Hradecka in the women’s doubles tennis gold medal match at the London Olympic Games

Serena and Venus Williams are one set away from Olympic gold. (Dominic Ebenbichler -- Reuters)

Serena and Venus Williams are one set away from Olympic gold. (Dominic Ebenbichler — Reuters)

Serena Williams of the U.S. serves over her sister, Venus Williams, to Czech Republic’s Andrea Hlavackova and Lucie Hradecka in the women’s doubles tennis gold medal match at the London Olympic Games, August 5, 2012. REUTERS/Dominic Ebenbichler (BRITAIN – Tags: OLYMPICS SPORT TENNIS)