Alcaraz moved up from No. 2 and swapped places with Sinner by virtue of a 6-2, 3-6, 6-1, 6-4 victory over him in Arthur Ashe Stadium on Sunday. Sinner had held No. 1 since making his debut there in June 2024, a 65-week stay. Alcaraz first reached that spot in September 2022 at age 19 -- making him the youngest No. 1 in ATP history -- by claiming his first major championship at that year's US Open. He relinquished that ranking in September 2023.
Carlos Alcaraz claimed the Cincinnati Open title after Jannik Sinner retired in the first set, marking Alcaraz's sixth title of the year and eighth Masters 1000.