Serena Williams of the US serves during the women's singles second round match against Caroline Garcia of France at the 2013 French Open tennis tournament at Roland Garros in Paris, France, on May 29, 2013. Serena Williams won 2-0. (Xinhua/Bai Xue)

Serena Williams of the US hits a return during the women's singles second round match against Caroline Garcia of France at the 2013 French Open tennis tournament at Roland Garros in Paris, France, on May 29, 2013. Serena Williams won 2-0. (Xinhua/Bai Xue)

Serena Williams of the US celebrates during the women's singles second round match against Caroline Garcia of France at the 2013 French Open tennis tournament at Roland Garros in Paris, France, on May 29, 2013. Serena Williams won 2-0. (Xinhua/Bai Xue)