
Alexander Zverev of Germany returns the ball against Stefanos Tsitsipas of Greece during the quarterfinal match of men's singles at the 2018 Rogers Cup in Toronto, Canada, Aug. 10, 2018. Alexander Zverev of Germany lost 1-2. (Xinhua/Zou Zheng)

Alexander Zverev of Germany returns the ball against Stefanos Tsitsipas of Greece during the quarterfinal match of men's singles at the 2018 Rogers Cup in Toronto, Canada, Aug. 10, 2018. Alexander Zverev of Germany lost 1-2. (Xinhua/Zou Zheng)