
Stan Wawrinka of Switzerland returns the ball during the men's singles second round match with Alexandr Dolgopolov of Ukraine at French Open Tennis Tournament 2017 in Roland Garros, Paris, France on June 1, 2017. Wawrinka won 3-0. (Xinhua/Han Yan)

Stan Wawrinka of Switzerland returns the ball during the men's singles second round match with Alexandr Dolgopolov of Ukraine at French Open Tennis Tournament 2017 in Roland Garros, Paris, France on June 1, 2017. Wawrinka won 3-0. (Xinhua/Han Yan)