Paula Creamer knocked in a long birdie at number 15 to retake the lead and held on en route to a one-stroke victory at the Samsung World Championship on Sunday.
It was the fourth victory of the year and eighth career for the 22-year-old Californian, who finished with a three-under-par 69.
The four wins this season are the most by an American player since Juli Inkster collected five in 1999.
Beyond adding to a strong campaign, it was an emotional win for Creamer, who broke into tears during a TV interview when she realised that she claimed the tournament near her hometown of Mountain View.
"This means a lot. That is (a) big win for myself," she said later. "I put so much pressure on myself every time I come here and to finally have one, it feels really good. I'm very excited.
"I briefly looked at my phone and people kept saying, 'Did I see you cry? I didn't think you had emotions and all of this.' It does. It really means a lot to me, this win."
Creamer came into the final round with a one-shot lead following a 68 on Saturday. That slim edge disappeared on the back nine Sunday when Korean Kim Song-hee birdied the 14th to pull even at eight-under.
As if losing the lead was not enough, two-time defending champion and world number one Lorena Ochoa and the Hall of Famer Inkster both notched a birdie on number 16 to pull within a stroke. Also moving to seven-under was Suzann Pettersen with a birdie at the 15th.
Despite the crowd at the top of the leaderboard, Creamer did not lose her focus, coming up with a birdie putt from 25 feet out on her next hole to move back ahead. She maintained that lead until the 18th, when a shaky birdie attempt nearly cost her. However, Creamer was able to lip in a par putt to seal the win, ending up at nine-under 279.
"Honestly, I didn't see it go in," Creamer said about the clinching putt. "All I heard was the people cheer for it, then I was like, it was like the longest two seconds of my life having it roll into the hole."