Sinner defeated Alcaraz in last month's Wimbledon final to secure his first title at SW19, and earlier in the season he swept aside Zverev in straight sets to win the Australian Open crown. For Zverev, that loss marked his third defeat in a major final, extending his painful wait for a breakthrough Grand Slam.

Should Alcaraz get through Zverev, he will either have another rendition of his superb rivalry with world No. 1 Jannik Sinner or a date with up-and-comer Térence Atmane in the final, whose immaculate run at Cincinnati has been one of the top stories across the sport.