Sofia Kenin of the United States hits a return during the women's singles quarterfinal match against Ons Jabeur of Tunisia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020. (Photos: Xinhua)

Petra Kvitova of the Czech Republic celebrates during the women's singles quarterfinal match against Ashleigh Barty of Australia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Sofia Kenin of the United States greets the audience after the women's singles quarterfinal match against Ons Jabeur of Tunisia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Sofia Kenin of the United States hits a return during the women's singles quarterfinal match against Ons Jabeur of Tunisia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Ashleigh Barty of Australia hits a return during the women's singles quarterfinal match against Petra Kvitova of the Czech Republic at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Ashleigh Barty of Australia celebrates during the women's singles quarterfinal match against Petra Kvitova of the Czech Republic at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Sofia Kenin of the United States hits a return during the women's singles quarterfinal match against Ons Jabeur of Tunisia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Ons Jabeur of Tunisia hits a return during the women's singles quarterfinal match against Sofia Kenin of the United States at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Sofia Kenin of the United States celebrates after the women's singles quarterfinal match against Ons Jabeur of Tunisia at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.

Ashleigh Barty of Australia hits a return during the women's singles quarterfinal match against Petra Kvitova of the Czech Republic at the Australian Open tennis championship in Melbourne, Australia on Jan. 28, 2020.