Petrissa Solja of Germany returns the ball during a women's singles round of 32 match between Feng Yalan of China and Petrissa Solja of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Feng Yalan of China returns the ball during a women's singles round of 32 match between Feng Yalan of China and Petrissa Solja of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Li Jiayi of China returns the ball during a women's singles round of 32 match between Li Jiayi of China and Hitomi Sato of Japan at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Timo Boll of Germany returns the ball during a men's singles round of 32 match between Xia Yizheng of China and Timo Boll of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Xia Yizheng of China returns the ball during a men's singles round of 32 match between Xia Yizheng of China and Timo Boll of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Wong Chun Ting of China's Hong Kong returns the ball during a men's singles round of 32 match between Ma Te of China and Wong Chun Ting of China's Hong Kong at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Xue Fei of China serves during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Ma Te of China returns the ball during a men's singles round of 32 match between Ma Te of China and Wong Chun Ting of China's Hong Kong at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Wong Chun Ting of China's Hong Kong returns the ball during a men's singles round of 32 match between Ma Te of China and Wong Chun Ting of China's Hong Kong at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Ma Te of China serves the ball during a men's singles round of 32 match between Ma Te of China and Wong Chun Ting of China's Hong Kong at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Chen Xingtong of China returns the ball during a women's singles round of 32 match between Chen Xingtong of China and her compatriot Wu Yang at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Dimitrij Ovtcharov of Germany serves during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Wu Yang of China serves during a women's singles round of 32 match between Chen Xingtong of China and her compatriot Wu Yang at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Chen Xingtong of China returns the ball during a women's singles round of 32 match between Chen Xingtong of China and her compatriot Wu Yang at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Wu Yang of China returns the ball during a women's singles round of 32 match between Chen Xingtong of China and her compatriot Wu Yang at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Li Jiayi of China serves during a women's singles round of 32 match between Li Jiayi of China and Hitomi Sato of Japan at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Xue Fei of China returns the ball during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Xue Fei of China returns the ball during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Hitomi Sato of Japan serves during a women's singles round of 32 match between Li Jiayi of China and Hitomi Sato of Japan at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Dimitrij Ovtcharov of Germany returns the ball during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Dimitrij Ovtcharov of Germany returns the ball during a men's singles round of 32 match between Xue Fei of China and Dimitrij Ovtcharov of Germany at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Li Jiayi of China returns the ball during a women's singles round of 32 match between Li Jiayi of China and Hitomi Sato of Japan at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)

Li Jiayi of China returns the ball during a women's singles round of 32 match between Li Jiayi of China and Hitomi Sato of Japan at the 2019 ITTF Czech Open in Olomouc, the Czech Republic, Aug. 22, 2019. (Xinhua/Shan Yuqi)