Serbia's Novak Djokovic returns the ball during the men's singles second round match against Uzbekistan's Denis Istomin at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 19, 2017. Djokovic lost 2-3. (Xinhua/Lui Siu Wai)
Serbia's Novak Djokovic returns the ball during the men's singles second round match against Uzbekistan's Denis Istomin at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 19, 2017. Djokovic lost 2-3. (Xinhua/Lui Siu Wai)