Jennifer Kupcho won the Chevron Championship after firing a closing two-over-par 74 in the California desert on Sunday.
It is the first LPGA Tour victory of her career.
The 24-year-old from Colorado – who led by six shots after a blistering eight-under-par 64 in Saturday’s third round – shrugged off a wobble on the back nine to complete a deserved victory in the opening Major of the season.
Kupcho finished on 14 under par for the tournament, two shots clear of Jessica Korda, who carded a closing 69 for a 12-under-par aggregate of 276.
Slovenian teenager Pia Babnik, just 18, finished third after a closing six-under-par 66 to finish on 11 under.
Japan’s Hinako Shibuno, France’s Celine Boutier, US star Lexi Thompson and 2021 champion Patty Tavatanakit were tied for fourth on 10 under.
Kupcho celebrated her triumph with the traditional winner’s leap into ‘Poppie’s Pond’ – the water hazard that surrounds the 18th green at Mission Hills Country Club.
The former amateur world No 1 – who turned professional before the 2019 season – is the last winner of the Chevron Championship in its California home.
The tournament is moving to Texas in 2023 after more than half a century in the desert community of Rancho Mirage.
The win confirms Kupcho as one of the brightest talents in women’s golf, and comes only three years after she won the Augusta National Women’s Amateur title in 2019.
Kupcho – who painted her fingernails green in honor of Augusta National for Sunday’s final round – admitted she had not expected her first LPGA title would be a Major.
“I’ve been so close a couple of times, it’s just really hard sometimes, but here I am,” Kupcho said. “A Major is crazy.”
Kupcho had built a formidable lead after her heroics on Saturday, which gave her ample breathing space at the top of the leaderboard.
She looked poised to wrap up victory at a canter after making birdies on the 2nd, 4th and 5th holes on Sunday, despite a bogey on the 3rd.
But her lead began to shrink after two more bogeys on the 8th and 10th holes.
She steadied with a birdie on the 11th, but then two jittery back-to-back bogeys on the 13th and 14th cut her lead to just two shots with Jessica Korda suddenly looking menacing.
Yet, just when the spectre of a collapse was rearing its head, Korda gave Kupcho a release from the pressure.
Korda’s bogey on the 15th restored Kupcho’s three-shot cushion with four holes remaining.
Kupcho then drilled her second shot from the fairway to within a few feet for a simple birdie on the 15th to go four shots clear to all but guarantee victory.
A par on the 16th left her four up with two to play, and despite a bogey on the 17th, Kupcho still had plenty of room to maneuver heading to the 18th.
A final bogey on the 18th – her fifth of the back nine and seventh of the round – could not deny her victory.
© Agence France-Presse