Aryna Sabalenka, of Belarus, reacts after defeating Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, left, shakes hands with Jessica Pegula, of the United States, after winning their semifinal match of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, reacts after defeating Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, returns a shot to Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Jessica Pegula, of the United States, returns a shot to Aryna Sabalenka, of Belarus, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, reacts after winning a point Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Jessica Pegula, of the United States, returns a shot to Aryna Sabalenka, of Belarus, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, returns a shot to Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Jessica Pegula, of the United States, returns a shot to Aryna Sabalenka, of Belarus, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Ciara, left, watches play between Jessica Pegula, of the United States, and Aryna Sabalenka, of Belarus, during the women's singles semifinals of the U.S. Open tennis championships in New York.

Aryna Sabalenka, of Belarus, reacts after winning a point Jessica Pegula, of the United States, during the women's singles semifinals of the U.S. Open tennis championships in New York.