Stan Wawrinka of Switzerland returns the ball during the men's singles third round match against Viktor Troicki of Serbia at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 20, 2017. Wawrinka won 3-1. (Xinhua/Bai Xue)
Stan Wawrinka of Switzerland returns the ball during the men's singles third round match against Viktor Troicki of Serbia at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 20, 2017. Wawrinka won 3-1. (Xinhua/Bai Xue)