(No. 2) Carlos Alcaraz def. (No. 1) Jannik Sinner 5-0 (Retired)

Carlos Alcaraz won his sixth title of the season and eighth career ATP Masters 1000 crown at the Cincinnati Open on Monday, as top ranked Jannik Sinner was forced to retire due to illness just 23 minutes into their championship match.

The much anticipated final marked their fourth meeting of 2025 and their first since Wimbledon. However, the match ended abruptly. Sinner looked visibly unwell in the Cincinnati heat, falling behind 0–5 in the opening set after committing nine unforced errors. During a changeover, he placed an ice pack on his head and called for the doctor, but ultimately retired after just 23 minutes of play.

The loss ended Sinner’s 26 match winning streak on hard courts and his 12 match overall streak. The defending Cincinnati champion had been aiming to become the first player since Roger Federer in 2014 and 2015 to win consecutive men’s titles at the tournament. Instead, he now faces a quick recovery in time for his US Open title defense, which begins this Sunday in New York.

For Alcaraz, the victory adds another milestone to his 2025 season. The Cincinnati Open, viewed as a key tune up event for the US Open, has produced champions who went on to win the year’s final Grand Slam in each of the past two seasons, a trend that could benefit the Spaniard as he heads to Flushing Meadows.