Victoria Mboko defeated Naomi Osaka 2–6, 6–4, 6–1 in the final of the Montreal WTA Masters 1000 on hard court on 7 August 2025, delivering a significant upset against the pre-match favourite. Osaka controlled the opening set with relative ease, but Mboko regrouped decisively in the second, breaking Osaka's serve at crucial moments to level the match. The third set proved decisive, with Mboko's aggressive baseline play and improved court positioning overwhelming Osaka, who struggled to find consistency as the match progressed. The upset victory marks a career-defining moment for Mboko, who entered as the underdog at 2.55 odds, while Osaka, favoured at 1.58, failed to claim what would have been a significant title on hard court. Mboko's maiden Masters 1000 triumph substantially elevates her ranking and suggests a potential shift in the competitive landscape at the top of the women's game.