Lydia Ko's putter went cold on a day she'd like to forget, as she finished 10th and five shots off the winner at the Honda LPGA Thailand event at Chonburi.
Ko started the final day in a share of fourth, two shots behind the leader, but the free-scoring that highlighted her first three rounds disappeared, as she strove for her second title of 2021.
The Kiwi made a bright start to her final round with a birdie at the par-four second, thanks to a brilliant putt that closed the gap to just one.
After three straight pars, Ko's produced a terrible iron shot that left her in big trouble at six and she couldn't make a long putt to avoid bogey.
Ko had opportunities to close out the front nine in style, but her putting was wayward and she slid down the leaderboard, as her rivals found birdies easy to come by.
The 24-year-old made the turn at 16-under par, six shots off the lead, and needed to come home at her best to claim her 17th career title.
After two straight birdies, Ko seemed to have found her groove, but it proved a false dawn, as the Kiwi quickly gave a shot back at 14.
Ko continued to spurn birdie chances down the stretch and reached the final hole at 16-under and in a share of 10th.
The Kiwi had a difficult chip shot to get up-and-down for par at the last, but tournament organisers suspended play for thunder and lightning in the area.
The suspension in play left a dramatic finish, with two Thailand players fighting it out for their home title. Ariya Jutanugarn carded an action-packed nine-under 63 - one shot off the course record - to hold the clubhouse lead at 23-under.
Compatriot Atthaya Thitikul came to the last needing an eagle for the title or a birdie to force a playoff, and after a long drive, she was forced to wait to complete the final hole.
Once played resumed, Ko finished with a birdie at the last to see her finish at 17-under and in a share of 10th, alongside German Caroline Masson.
Thitikul needed a birdie to force a playoff, but she could only manage a par on the final hole to hand Jutanugarn the title at 22-under par.
Despite the disappointing finish, Ko moves to the top of the year-long Race to CME Globe, just ahead of American Nelly Korda.