
Serbia's Novak Djokovic returns the ball against Austria's Dominic Thiem during the semifinal match of men's singles at the Italian Open tennis tournament in Rome, Italy, May 20, 2017. Novak Djokovic won 2-0. (Xinhua/Jin Yu)

Serbia's Novak Djokovic returns the ball against Austria's Dominic Thiem during the semifinal match of men's singles at the Italian Open tennis tournament in Rome, Italy, May 20, 2017. Novak Djokovic won 2-0. (Xinhua/Jin Yu)