Wang Xinyu of China serves during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Xinyu of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Yafan of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Yafan of China serves during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Yafan of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Xinyu of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Xinyu of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Yafan of China returns the ball during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Yafan of China reacts during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)

Wang Xinyu of China reacts during the women's singles first round match between Wang Yafan of China and her compatriot Wang Xinyu at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Hou Zhaokang)