
Daria Kasatkina of Russia serves during the women's singles first round match against Wang Qiang of China at the 2017 US Open tennis tournament in New York, the United States, Aug. 30, 2017. (Xinhua/Li Muzi)

Daria Kasatkina of Russia serves during the women's singles first round match against Wang Qiang of China at the 2017 US Open tennis tournament in New York, the United States, Aug. 30, 2017. (Xinhua/Li Muzi)