Italy's Jannik Sinner celebrates after winning the semifinal tennis match against Tommy Paul, of the United States, at the Italian Open, in Rome.

Italy's Jannik Sinner returns the ball to Tommy Paul, of the United States, during their semifinal tennis match at the Italian Open, in Rome.

Tommy Paul, of the United States, serves the ball to Italy's Jannik Sinner during their semifinal tennis match at the Italian Open, in Rome.

Italy's Jannik Sinner returns the ball to Tommy Paul, of the United States, during their semifinal tennis match at the Italian Open, in Rome.

Tommy Paul, of the United States, returns the ball to Italy's Jannik Sinner during their semifinal tennis match at the Italian Open, in Rome.

Italy's Jannik Sinner serves the ball to Tommy Paul, of the United States, during their semifinal tennis match at the Italian Open, in Rome.

Tommy Paul, of the United States, returns the ball to Italy's Jannik Sinner during their semifinal tennis match at the Italian Open, in Rome.

Italy's Jannik Sinner returns the ball to Tommy Paul, of the United States, during their semifinal tennis match at the Italian Open, in Rome.

Italy's Jannik Sinner returns the ball to Tommy Paul, of the United States, during their semifinal tennis match at the Italian Open, in Rome.

Tommy Paul, of the United States, returns the ball to Italy's Jannik Sinner during their semifinal tennis match at the Italian Open, in Rome.