Petra Kvitova of Czech Republic returns a shot during the women's singles third round match against Anett Kontaveit of Estonia at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Petra Kvitova lost 0-2. (Xinhua/Chen Yichen)

Petra Kvitova of Czech Republic returns a shot during the women's singles third round match against Anett Kontaveit of Estonia at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Petra Kvitova lost 0-2. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia reacts during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia competes during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia returns a shot during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Petra Kvitova of Czech Republic returns a shot during the women's singles third round match against Anett Kontaveit of Estonia at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Petra Kvitova lost 0-2. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia returns a shot during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia returns a shot during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia returns a shot during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)

Anett Kontaveit of Estonia returns a shot during the women's singles third round match against Petra Kvitova of Czech Republic at the French Open Tennis Tournament 2018 in Paris, France on June 2, 2018. Anett Kontaveit won 2-0. (Xinhua/Chen Yichen)