
Janko Tipsarevic of Serbia returns the ball during men's single's first round match against Grigor Dimitrov of Bulgaria at the 2019 Australian Open in Melbourne, Australia, Jan. 14, 2019. Grigor Dimitrov won 3-1. (Xinhua/Hu Jingchen)

Janko Tipsarevic of Serbia returns the ball during men's single's first round match against Grigor Dimitrov of Bulgaria at the 2019 Australian Open in Melbourne, Australia, Jan. 14, 2019. Grigor Dimitrov won 3-1. (Xinhua/Hu Jingchen)