Timea Babos of Hungary and Kristina Mladenovic (L) of France celebrate after the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019. (Photos: Xinhua)

Timea Babos (R) of Hungary and Kristina Mladenovic of France talk during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos of Hungary and Kristina Mladenovic (L) of France celebrate after the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Anna-Lena Groenefeld (R) of Germany and Demi Schuurs of the Netherlands compete during the doubles round robin match against Timea Babos of Hungary and Kristina Mladenovic of France at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France compete during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Anna-Lena Groenefeld of Germany and Demi Schuurs (L) of the Netherlands talk during the doubles round robin match against Timea Babos of Hungary and Kristina Mladenovic of France at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (L) of Hungary and Kristina Mladenovic of France compete during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France react during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos of Hungary and Kristina Mladenovic (L) of France celebrate after the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France take a break during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Anna-Lena Groenefeld (Top R) of Germany and Demi Schuurs (Top L) of the Netherlands compete during the doubles round robin match against Timea Babos of Hungary and Kristina Mladenovic of France at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Anna-Lena Groenefeld of Germany and Demi Schuurs (R) of the Netherlands compete during the doubles round robin match against Timea Babos of Hungary and Kristina Mladenovic of France at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France compete during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France talk during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France talk during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Anna-Lena Groenefeld of Germany and Demi Schuurs (L) of the Netherlands react during the doubles round robin match against Timea Babos of Hungary and Kristina Mladenovic of France at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France compete during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (R) of Hungary and Kristina Mladenovic of France talk during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.

Timea Babos (L) of Hungary and Kristina Mladenovic of France compete during the doubles round robin match against Anna-Lena Groenefeld of Germany and Demi Schuurs of the Netherlands at the WTA Finals Tennis Tournament in Shenzhen, south China's Guangdong Province, Oct. 30, 2019.