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

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