Canadian teenager Victoria Mboko conquered four-time Grand Slam champion Naomi Osaka 2-6, 6-4, 6-1 on Thursday, capping a fairytale run at the Canadian Open with her first WTA title.

Mboko, playing in her first WTA final, denied Osaka her first tour-level title since the 2021 Australian Open.

Over the course of the two-hour, four-minute contest, the 18-year-old wore down the former world number one who has struggled to find consistency since returning from maternity leave early in 2024.

Ranked outside the top 300 to start the season, Mboko had climbed to 85th entering the week and is now projected to rise to 34th after the tournament.

Before an ecstatic centre court crowd, she converted eight of her nine break points, seizing her fourth win of the week over a Grand Slam winner.

She ousted former Australian Open champion Sofia Kenin in the second round, toppled reigning French Open champion Coco Gauff in the fourth, before saving a match point en route to a semi-final victory over former Wimbledon winner Elena Rybakina.

Displaying vintage power and precision, Osaka gave her inexperienced opponent little room to maneuver in the first set, gaining an early break on the way to a 3-0 lead and pocketing the set when Mboko misfired on two forehands to drop her serve a second time.

Mboko turned the tide in a second set that featured seven total breaks of serve. Osaka looked bewildered as her opponent ramped up the pressure, the Canadian breaking her at love for a 5-2 lead.

Serving for the set, however, Mboko coughed up three double faults and was broken. Osaka capitalised on the reprieve with a hold at love, but Mboko took the set in the next game when Osaka sailed a forehand long on set point.

Osaka appeared demoralised as she was broken at love to open the third set.

Mboko couldn't consolidate the break, but Osaka was on the ropes again in the third game, drawing a warning for batting a ball skyward in frustration after missing her first serve on break point - which she surrendered with another errant forehand.

That launched a run of five straight games for Mboko. When Osaka smacked a backhand into the net on match point, Mboko dropped to the court as the crowd roared out one more ovation.

Osaka, who had appeared energised in Montreal after a coaching shakeup, posted her best performance in a WTA 1000 tournament since she reached the final at Miami in 2022. (AFP)