BIRMINGHAM, Ala.

In some of the bleakest moments during Ariya Jutanugarn’s back-nine collapse at the U.S. Women’s Open, the 22-year-old from Thailand would take a deep breath, smile to herself and think happy thoughts.

The mind tricks weren’t working, but she wasn’t going to stop trying.

Finally, after an excruciating few hours of golf, the positive vibes came true.

Jutanugarn lost a seven-shot lead on the back nine before prevailing on the fourth hole of a playoff to win at Shoal Creek on Sunday for her second major championship.

She made a nearly-perfect bunker shot to within a foot of the cup on the tournament clinching hole, beating South Korea’s Hyo- Joo Kim, who shot a 5- under 67 in the final round to force the playoff.

It was not an easy up-and-down for Jutanugarn, who said she didn’t have a particularly good lie in the sand. Somehow, she kept her cool.

She felt even better when the ball rolled close enough for an easy putt. A collapse that would have gone down in U.S. Women’s Open lore was about to be averted.

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 shots.

But a triple bogey on No. 10 cut the lead to four and rocked her confidence, especially with her 3-wood. 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.

Jutanugarn and Kim shot 11-under 277 in regulation.

In the end, Jutanugarn’s slow-motion collapse set up an emotional victory and her second major win. 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 right next to cup 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.