Victoria Azarenka of Belarus hits a return during her women's singles second round match against Annika Beck of Germany at the French Open tennis tournament at the Roland Garros stadium in Paris May 30, 2013. Victoria Azarenka won 2-0. (Xinhua/Bai Xue)

Maria Sharapova of Russia hits a return during her women's singles second round match against Eugenie Bouchard of Canada at the French Open tennis tournament at the Roland Garros stadium in Paris May 30, 2013. (Xinhua/Tang Shi)

Maria Sharapova of Russia hits a return during her women's singles second round match against Eugenie Bouchard of Canada at the French Open tennis tournament at the Roland Garros stadium in Paris May 30, 2013. (Xinhua/Tang Shi)

Victoria Azarenka of Belarus celebrates during her women's singles second round match against Annika Beck of Germany at the French Open tennis tournament at the Roland Garros stadium in Paris May 30, 2013. Victoria Azarenka won 2-0. (Xinhua/Bai Xue)

Maria Sharapova of Russia serves during her women's singles second round match against Eugenie Bouchard of Canada at the French Open tennis tournament at the Roland Garros stadium in Paris May 30, 2013. (Xinhua/Tang Shi)