Hee Young Park birdied the third extra hole of a playoff against Angela Stanford after the pair had finished three shots ahead of Scotland's Catriona Matthew at the Grey Silo Golf Club in Waterloo in Ontario.
The current 37th world ranked player produced a final nine of 30 for a round of 65 to win her second LPGA title having won the CME Group Titleholders event late in 2011.
A prolific winner on the Korean LPGA Tour before joining the LPGA Tour in 2008, the 26 year old reversed some ordinary recent form including a missed cut at the recent US Women's Open to win with a winning total of 26 under in what was a birdie fest.
The other Park mentioned earlier, Inbee Park, finished 14th.
Karrie Webb finished as the leading Australian when 35th while rookie Julia Boland was the only other to make the cut when 65th.
The LPGA Tour now moves to Ohio for the Marathons Classic.