Venus Williams of the USA returns a ball to Peng Shuai from China during their women’s first round match in the China Open tennis tournament at the National Tennis Center in Beijing, China 03 October 2016. Peng later defeated Williams in 7-5, 6-1. EPA/ROLEX DELA PENA

Agnieszka Radwanska of Poland in action during a women’s singles match against Ekaterina Makarova of Russia in the China Open tennis tournament at the National Tennis Center in Beijing, China 03 October 2016. EPA/WU HONG

Caroline Wozniacki of Denmark in action against Roberta Vinci of Italy during the women’s singles match for the China Open tennis tournament at the National Tennis Center in Beijing, China, 04 October 2016. EPA/WU HONG

Timea Bacsinszky of Switzerland reacts as she in action against Lara Arruabarrena of Spain during the women’s singles match for the China Open tennis tournament at the National Tennis Center in Beijing, China, 03 October 2016. EPA/WU HONG

Madison Keys of USA in action against Kristina Mladenovic of France during the women’s singles match for the China Open tennis tournament at the National Tennis Center in Beijing, China, 03 October 2016. EPA/WU HONG