American Brittany Lincicome fired a two-under-par 70 on Sunday to win the LPGA Canadian Women's Open by one stroke, capturing her second victory of the year and the fifth of her career.
Lincicome finished 72 holes at Hillsdale Country Club on 13-under-par 275 to edge compatriots Stacy Lewis and Michelle Wie, the defending champion, with two more Americans, Angela Stanford and Cristie Kerr, sharing fourth on 277.
Since joining the tour in 2005, Lincicome had never won more than one title in a season, but has already doubled up this year, having also won the ShopRite LPGA Classic in June.
The $337,000 top prize also pushed Lincicome beyond $4 million in career LPGA earnings.
South Koreans Hee-Won Han, Jenny Shin, Na Yeon Choi and Jiyai Shin shared sixth on 278, one stroke ahead of compatriots Sun Young Yoo and Song-Hee Kim.
The final round of the $2.25 million event began with morning threesomes and organisers started early to complete play ahead of the approaching remnants of the storm that had been Hurricane Irene.
Lincicome started the day one stroke behind Wie, Japan's Ai Miyazato and US rookie Tiffany Joh but quickly charged to the top as the co-leaders faded in windy and rainy conditions.
Lincicome opened with a birdie at the par-five first and followed up with birdies at the par-five fifth and par-four seventh to grab a two-stroke lead.
But Lincicome stumbled with a bogey at the par-four 12th, falling only one stroke ahead of Kerr and Lewis, who were both ahead of her on the course.
Lewis reached the clubhouse at 12-under 276, posting the score to beat with Lincicome leading her by a stroke with five holes remaining.
Lewis birdied three of the first four holes, the par-five 10th and 12th in a bogey-free round.
Kerr, who opened with a birdie but took a bogey at the second, began the back nine with back-to-back birdies to put herself in the title hunt and birdied the par-five 14th to match Lincicome for the lead.
Wie, who opened with a birdie but stumbled back with bogeys at the third and ninth holes, birdied the 13th and par-three 15th to move to within a stroke of the lead.
But a bogey at the 16th dropped Wie one back and Kerr stumbled in with bogeys at 16 and 17 to finish on 277, leaving Lincicome alone at the top.
Lincicome parred the final five holes to reach the clubhouse on top with Wie needing a birdie to force a play-off but instead settling for a par.