Playing in her first WTA 1000 final since 2022, the Japanese made an outstanding start to the Montreal title match and took the opening set versus Canadian wildcard Victoria Mboko with a 6-2 scoreline. But then, the former world No. 1's level dropped and the 18-year-old teenage sensation went on to complete a 2-6 6-4 6-1 win.

Naomi Osaka reacts to playing Victoria Mboko in the final of the National Bank Open after Mboko called Osaka her "idol" years back.

Mboko, 18 and playing in her first WTA final, denied Osaka her first tour-level title since the 2021 Australian Open. Despite being a set down, she wore down the Japanese star, 27, who has struggled to find consistency since returning from maternity leave early in 2024.