Korda now has five wins this year – four on the LPGA Tour to match Jin Young Ko's total, plus a gold medal success at the Tokyo Olympics – but none of the others have been this wild.

"I almost kind of lost faith," Korda said.

The American dropped out of the lead on the 17th hole at Pelican Golf Club by chopping her way to a triple bogey to fall two shots behind her playing partner Thompson.

However, she answered with an 18-foot birdie putt on the final hole for a one-under 69 and got into a playoff when Thompson made a second straight bogey for 69.

They were joined at 17-under 263 by defending champion Sei Young Kim (67) and Lydia Ko (66), neither of whom expected to be playing extra holes until Thompson and Korda imploded over the final two holes of regulation.

Korda ended it quickly though with her second birdie on the 18th hole, this one from 12 feet.

"I just found myself probably the best putt," Korda said.

"Putted two times in a row, and went in really nicely."

The victory in Florida paid off handsomely for the 23-year-old.

She secured her No.1 ranking and moved 12 points ahead of Jin Young Ko for LPGA player of the year, going into the season-ending CME Group Tour Championship next week.

Thompson, whose most recent of her 11 LPGA Tour wins was in June 2019, has struggled to close out when in contention in recent time and now has gone 38 events since her last success.

Canadian Brooke Henderson (65) finished alone in fifth at 14-under while Korda's sister Jessica carded a 67 on Sunday to share 12th at 11-under.

The Australians in the field Katherine Kirk (70, five-under) and Oh (72, three-under) finished in a share of 40th and 52nd respectively. However, Oh’s Sunday ace at the par-3 12th earned her a two-year lease on Lamborghini.