
Naomi Osaka of Japan hits a return during the women's singles quarterfinal match against Zhang Shuai of China at China Open tennis tournament in Beijing, China, Oct. 5, 2018. Naomi Osaka won 2-1. (Xinhua/Kong Hui)

Naomi Osaka of Japan hits a return during the women's singles quarterfinal match against Zhang Shuai of China at China Open tennis tournament in Beijing, China, Oct. 5, 2018. Naomi Osaka won 2-1. (Xinhua/Kong Hui)

Juan Martin Del Potro of Argentina celebrates victory for the men's singles quarterfinal match against Filip Krajinovic of Serbia at China Open tennis tournament in Beijing, China, Oct. 5, 2018. Juan Martin Del Potro won 2-0. (Xinhua/Song Yanhua)