Carlos Alcaraz won the Cincinnati Open on Monday after Jannik Sinner was forced to retire due to illness. Alcaraz was already up big on Sinner, the World No. 1, when he had to retire. Sinner told the crowd that he hoped to play after feeling bad overnight, but he couldn't make it work.

US Open champion Jannik Sinner has provided a scare before next week's tournament after he retired from the Cincinnati Open final against Carlos Alcaraz. Sinner was only on court for 24 minutes, but was out of sorts in hot conditions in Ohio and broken three times by rival Alcaraz to trail 5-0.

Jannik Sinner insisted on Monday he would be ready to defend his US Open crown after illness forced him to retire from his Cincinnati Open final clash with Carlos Alcaraz.World number one Sinner -- who is due to to play in the US Open's revamped mixed doubles tournament on Tuesday -- conceded defeat to Alcaraz on Monday after going 5-0 down in the first set.