Jannik Sinner, of Italy, waves after defeating Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Felix Auger-Aliassime, of Canada, waves to the crowd after losing to Jannik Sinner, of Italy, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Jannik Sinner, of Italy, shakes hands after defeating Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Jannik Sinner, of Italy, returns a shot to Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Felix Auger-Aliassime, of Canada, returns a shot against Jannik Sinner, of Italy, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Jannik Sinner, of Italy, returns a shot against Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Felix Auger-Aliassime, of Canada, returns a shot to Jannik Sinner, of Italy, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Jannik Sinner, of Italy, returns a shot to Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Felix Auger-Aliassime, of Canada, reacts after missing a shot by Jannik Sinner, of Italy, during the men's singles semifinals of the U.S. Open tennis championships in New York.

Jannik Sinner, of Italy, returns a shot to Felix Auger-Aliassime, of Canada, during the men's singles semifinals of the U.S. Open tennis championships in New York.