Danielle Collins of the United States reacts during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic hits a return during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final. (Photos: Xinhua/Hu Jingchen)

Danielle Collins of the United States reacts during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic hits a return during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic celebrates after the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic celebrates during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic (R) shakes hands with Danielle Collins of the United States after the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic hits a return during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Petra Kvitova of the Czech Republic hits a return during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.

Danielle Collins of the United States serves during the women's singles semifinal match between Petra Kvitova of the Czech Republic and Danielle Collins of the United States at the 2019 Australian Open in Melbourne, Australia, on Jan. 24, 2019. Kvitova won 2-0 to enter the final.