Belinda Bencic, of Switzerland, returns to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, reacts after defeating Anastasia Pavlyuchenkova, of the Russian Olympic Committee, in the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, returns to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, serves to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, reacts during the quarterfinal round of the women's tennis competition against Anastasia Pavlyuchenkova, of the Russian Olympic Committee, at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, returns to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, returns to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, returns to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, serves to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, returns to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, returns to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, returns to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, returns to Anastasia Pavlyuchenkova, of the Russian Olympic Committee, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Belinda Bencic, of Switzerland, reacts after defeating Anastasia Pavlyuchenkova, of the Russian Olympic Committee, in the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)

Anastasia Pavlyuchenkova, of the Russian Olympic Committee, serves to Belinda Bencic, of Switzerland, during the quarterfinal round of the women's tennis competition at the 2020 Summer Olympics, Wednesday, July 28, 2021, in Tokyo, Japan. (AP Photo/Patrick Semansky)