Leona Maguire came up just short in her bid for a first LPGA Tour victory as Nelly Korda held her nerve on the final green at Blythefield Country Club.
A career-best payday of $214,000 (€180,500) will be of limited consolation after the Cavan golfer saw a 25-foot eagle putt to guarantee her a play-off slide by on the final hole at the Meijer LPGA Classic.
Instead, world no. 4 Korda escaped a greenside bunker to birdie for a 25-under total, while Maguire ended up three-putting to finish two back.
The bogey-free final round of 66 ensured Maguire's fifth LPGA Tour top-10 and another runner-up finish, following April's Lotte Championship, as she bids to become the first Irish winner on the tour.
Maguire began three shots behind Korda in the final group but had cancelled out that headstart by the fourth hole with a hat-trick of birdies.
Another birdie at the eighth kept it level at the turn before Korda stepped up the pace. She had restored her three-stroke advantage by the 15th after three birdies and an eagle at 14, with one bogey in between, as Maguire could only birdie 14 in reply.
A two-shot swing at 16 breathed new life into Maguire's challenge, trickling in a tricky birdie putt as Korda three-putted from 10 feet.
Maguire escaped the trees at 17 for a par but while Korda opened the door when finding a bunker at the last, the 22-year-old American was able to close it just as fast for the fifth LPGA Tour win of her career ahead of next week's Women's PGA Championship.
In-Gee Chun, of South Korea, shot the round of the day, a 63, to give her a share of third with American Brittany Altomare on 21-under.