Overnight co-leader Lydia Ko has been forced to settle for a tie for fourth after carding a par 72 on the final day of the LPGA Tour event in South Korea.
The 18-year-old New Zealander finished two shots behind American Lexi Thompson, who took out the KEB Hana Bank Championship in Incheon by shooting a 69 to be 15-under-par for the tournament.
Thompson had been runner-up when Ko claimed her first major title with victory in the Evian Championship in France in September.
She had gone into Sunday in a tie for third, one shot behind Ko and fellow overnight leader Sung Hyun Park of South Korea.
World No.2 Ko, competing in her country of birth and bidding for her third title in four tournaments, had an up-and-down final round, mixing three birdies with three bogeys.
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When she and playing partner Park arrived at the par-five 18th hole, they both needed an eagle to force Thompson into a play-off.
Park was able to secure a birdie that gave her a share of second with Taiwan's Yani Tseng, but Ko had to be content with a par.
Also in the three-way tie for fourth was South Korean Amy Yang, who produced a scorching finish.
Yang birdied every one of the last nine holes as she fired a 10-under 62.
