Maria Sharapova of Russia reacts during the quarter final match of Porsche Tennis Grand Prix against Ana Ivanovic of Serbia in Stuttgart, Germany, on April 26, 2013. Maria Sharapova won 2-1. (Xinhua/Ma Ning)
Maria Sharapova of Russia returns a ball during the quarter final match of Porsche Tennis Grand Prix against Ana Ivanovic of Serbia in Stuttgart, Germany, on April 26, 2013. Maria Sharapova won 2-1. (Xinhua/Ma Ning)
Maria Sharapova of Russia returns a ball during the quarter final match of Porsche Tennis Grand Prix against Ana Ivanovic of Serbia in Stuttgart, Germany, on April 26, 2013. Maria Sharapova won 2-1. (Xinhua/Ma Ning)
Ana Ivanovic of Serbia returns a ball during the quarter final match of Porsche Tennis Grand Prix against Maria Sharapova of Russia in Stuttgart, Germany, on April 26, 2013. Ana Ivanovic lost 1-2. (Xinhua/Ma Ning)
Maria Sharapova of Russia returns a ball during the quarter final match of Porsche Tennis Grand Prix against Ana Ivanovic of Serbia in Stuttgart, Germany, on April 26, 2013. Maria Sharapova won 2-1. (Xinhua/Ma Ning)
Ana Ivanovic of Serbia returns a ball during the quarter final match of Porsche Tennis Grand Prix against Maria Sharapova of Russia in Stuttgart, Germany, on April 26, 2013. Ana Ivanovic lost 1-2. (Xinhua/Ma Ning)