Rebecca Peterson of Sweden returns a shot after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Rebecca Peterson of Sweden celebrates after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania reacts after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Rebecca Peterson of Sweden returns a shot after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania greets spectators after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania returns a shot after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania serves after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania serves after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania celebrates after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Simona Halep of Romania reacts after the women's singles first round match between Simona Halep of Romania and Rebecca Peterson of Sweden at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Hou Zhaokang/Xinhua)

Elina Svitolina of Ukraine serves during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Anastasija Sevastova of Latvia returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Elina Svitolina of Ukraine returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Elina Svitolina of Ukraine returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Anastasija Sevastova of Latvia returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Elina Svitolina of Ukraine returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Anastasija Sevastova of Latvia returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)

Elina Svitolina of Ukraine returns a shot during the women's singles first round match between Elina Svitolina of Ukraine and Anastasija Sevastova of Latvia at the 2019 China Open tennis tournament in Beijing, capital of China, Sept. 29, 2019. (Xinhua/Jia Haocheng)