England's Jodi Ewart Shadoff finished joint second at the Marathon Classic alongside Lydia Ko, whose dramatic late collapse allowed Danielle Kang to win the title by one shot.
New Zealand's Ko, 23, had a five-shot lead with six holes to play at Highland Meadows in Ohio.
But she hit two bogeys and a double-bogey on the last to post a two-over-par 73 to finish on 14 under overall.
American Kang's three-under 68 saw her win the title on 15 under.
"My caddie looked at me and said, 'You're right in it,'" said Kang, 27, who also won the Drive On Championship last week, the first LPGA Tour event since the coronavirus shutdown.
"I looked at him and said, 'I'm five down with six holes to go' but I kind of liked that mentality, made some good birdies coming in and kept it together.
" Ewart Shadoff, 32, hit a four-under 67 to join Ko, who had led by four shots overnight, in second place.