
Alexander Zverev of Germany serves during the final match of men's singles against Novak Djokovic of Serbia at the Italian Open tennis tournament in Rome, Italy, May 21, 2017. Alexander Zverev won 2-0. (Xinhua/Jin Yu)

Alexander Zverev of Germany serves during the final match of men's singles against Novak Djokovic of Serbia at the Italian Open tennis tournament in Rome, Italy, May 21, 2017. Alexander Zverev won 2-0. (Xinhua/Jin Yu)