Elina Svitolina of Ukraine hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Dalila Jakupovic of Slovenia hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Elina Svitolina of Ukraine hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Dalila Jakupovic of Slovenia hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Elina Svitolina of Ukraine hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Dalila Jakupovic of Slovenia hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)

Elina Svitolina of Ukraine hits a return during the women's singles first round match between Elina Svitolina of Ukraine and Dalila Jakupovic of Slovenia at WTA Guangzhou Open tennis tournament in Guangzhou, capital of south China's Guangdong Province, Sept. 17, 2019. (Xinhua/Lu Hanxin)