Roger Federer of Switzerland gives a ball to the audience after the men's singles fourth round match against Kei Nishikori of Japan at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 22, 2017. Federer won 3-2. (Xinhua/Bai Xue)
Roger Federer of Switzerland gives a ball to the audience after the men's singles fourth round match against Kei Nishikori of Japan at the Australian Open Tennis Championships in Melbourne, Australia, Jan. 22, 2017. Federer won 3-2. (Xinhua/Bai Xue)