Answer: Carlos Alcaraz
Notes: Carlos Alcaraz won the men's singles tennis title at Cincinnati Open after top seed Jannik Sinner retired due to illness on August 18, 2025. Alcaraz ended world number one Sinner’s 26-match winning streak on hard courts while leading 5-0 in the first set. This was Alcaraz’s third Masters 1000 title of the season after Monte Carlo and Rome. Sinner, aiming to defend his Cincinnati title like Roger Federer in 2015, retired after just 23 minutes.
