(Reuters) - American Lexi Thompson took advantage of a faltering final round by world number two Lydia Ko to claim the $2 million LPGA KEB Hana Bank Championship by one shot in Incheon on Sunday.
The world number five fired a final round three-under-par 69 at the Sky 72 Club, west of Seoul, for a 15-under total of 273 to leapfrog joint overnight leader Ko (72) and claim her sixth LPGA Tour title and second of the year.
"Getting the win, it means so much," Thompson said at the trophy presentation.
Ko's difficult day was complete when she missed an eight foot birdie putt on the last that would have allowed her to reclaim the world number one ranking from South Korean Park In-bee. Instead she finished in a share of fourth.
Former world number one Yani Tseng (68), who has fallen outside the top 50, continued her return to form by finishing joint second with South Korean Park Sung-hyun (71), who struggled with a cold putter on the back nine on Sunday.
South Korean Amy Yang struck a joint course record 62 to vault up the leaderboard to claim a share of fourth on 13-under, alongside Ko and American Gerina Piller (67).
Ko and Park Sung-hyun had started the round with a share of the lead but the New Zealand teenager never really got going on Sunday with three bogeys in the middle of her round to drop off the pace.
The big-hitting Park, three times a winner on the Korean Tour this year, was always in touch but a string of missed birdie efforts over the closing holes prevented her putting more pressure on Thompson.
The 20-year-old American had no such problems with the short stick and recorded a run of three straight birdies from the seventh to move clear.
Although she dropped a shot on the par-four 11th she produced a neat up-and-down on the driveable par-four 15th to pick up another birdie and stay clear as she calmly parred her way home.
The LPGA Tour continues its Asian swing next week at the Taiwan Championships, where Park In-bee is the defending champion.
(Writing by Patrick Johnston in Singapore; Editing by John O'Brien)