Park has been a consistent money winner throughout her career but this was her first win on a recognised tour since joining the LPGA Tour.
Park and Gal led into the final day but Park bounced back from an early bogey to take the lead and never let go.
Karrie Webb was the only Australian to have qualified for the event but after a fast start on Thursday the best she could do was 29th.
The event brings to a close the regular LPGA Tour schedule leaving Yani Tseng as the clear winner of money list and player of the year honours.
Tseng finished the year with more than US$2.9 million in earnings nearly twice that of nearest rival Cristie Kerr.
Unsurprisingly Webb was also named LPGA Tour Player of the Year having won seven titles and 11 world wide in 2011.
Karrie Webb finished 14th with US$757,000.
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