Swinging with metronomic consistency and putting with unerring accuracy, she finished at 14-under 274 at the historic Kooyonga course that has hosted five men's Australian Opens.
Ko is already a 10-times winner on the Korean LPGA. Last October she captured the LPGA KEB Hana Bank Championship title and earned a ticket to the lucrative U.S. women's tour.
On Sunday, in another tournament sanctioned by the LPGA circuit, the 22-year-old became only the second player after Beverly Hanson in 1951 to claim an LPGA Tour title in her first start as a member.
Ko acknowledged she had been nervous trying to maintain her final-round lead, and credited her Australian caddie Dean Herden for keeping her from getting too excited.
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"Did you see Dean's face, really scary," she said at the victory presentation on the 18th green, eliciting a roar of laughter from onlookers.
"First time in Australia ... my goal was to make the cut and enjoy the game but I did win."
(Reporting by Andrew Both in Adelaide, South Australia; Editing by Greg Stutchbury)
