Ariya Jutanugarn wins the U.S. Women’s Open in a playoff.

BIRMINGHAM, Ala. — Ariya Jutanugarn lost a seven-shot lead on the back nine and then prevailed on the fourth hole of a playoff to win the U.S. Women’s Open on Sunday at Shoal Creek.

Jutanugarn, a 22-year-old from Thailand, made a clutch bunker shot to within a foot of the hole to save par, beating South Korea’s

Hyo-Joo Kim, who shot a 5-under 67 in the final round to force the playoff.

Jutanugarn started the day with a four-shot lead over Australia’s Sarah Jane Smith and looked like she might win easily after opening with a 4 under on the front nine to stretch her lead to seven strokes.

But a triple bogey on No. 10 cut the lead to four and seemed to shake her confidence. She still had a two-shot lead with two holes remaining, but closed with back-to-back bogeys to fall into a playoff after shooting 73.

In the end, the excruciating collapse set up an emotional victory and her second major championship. She also won the Women’s British Open in 2016.

The format for the playoff was a two-hole aggregate on 14 and 18, but the players were still tied after the two holes. The format then switched to sudden death, alternating between the same holes.

Kim looked like she might win the two-hole aggregate after making a long birdie putt on 14 while Jutanugarn settled for par. But Kim made bogey — her first of the day — on 18 while Jutanugarn made par again to send the format to sudden death.

On the fourth playoff hole at 18, both players went into greenside bunkers. Kim’s shot out of the bunker was decent, but Jutanugarn’s was phenomenal, rolling to within a foot of the hole and setting up an easy par putt.

Kim missed her putt for par and Jutanugarn tapped in for the win, turning toward her caddie and family for a happy, tearful embrace.