Jannik Sinner retired with an apparent illness 23 minutes into the first set of the Cincinnati Open final against Carlos Alcaraz.

Sinner retired with apparent illness in the first set of Monday's Cincinnati Open final against Alcaraz after digging a 5-0 deficit. Sinner remained on the court for the trophy ceremony and addressed his condition while speaking with the crowd. He didn't offer specifics, but said that he "didn't feel great."

The latest chapter of the Jannik Sinner-Carlos Alcaraz rivalry took a stunning turn on Monday when world No. 1 Sinner retired in the first set of the Cincinnati Open final due to an unspecified health issue.