American Stacy Lewis won the Kraft Nabisco Championship, the LPGA's first major of the year, by three shots.
Lewis, 26, started the final round two behind Taiwan's world number one and defending champion Yani Tseng but erased that deficit within four holes.
Birdies on nine and 12 put Lewis ahead and a par on 17, where Tseng carded a bogey, all but sealed her first major.
"I just hung in there and made some key putts," said Lewis, who shot a three-under-par 69 to finish on 13 under.
Tseng was favourite to wrap up her fourth major title after a bogey-free third round of 66 had catapulted her to the top of the leaderboard.
But Lewis, who shot a 78 to lose the 2008 US Open after going into the final round as leader, birdied the second and third to draw level with her playing partner.
She coped admirably with the windy conditions at Mission Hills in California, edging ahead with a four at the par-five ninth before a fourth birdie followed on the 12th.
The tournament was effectively won on the short 17th when Lewis drained a long, curling, par putt while Tseng had to settle for a bogey four after missing a shorter putt.
"I couldn't believe I made it," said Lewis, whose career was saved as a teenager by surgery to correct a curvature of her spine.
"I knew I had a good shot at winning from there. I was just trying to control my emotions and stay calm."
Fellow American Morgan Pressel began the day on eight under par and birdies at the second and fifth briefly lifted her into contention.
But a triple bogey seven at the sixth checked her progress and she dropped four more shots with an eight at the par-four 16th to tie for third on four under par with compatriots Katie Futcher and Angela Stanford.
Michelle Wie finished in the top 10 at a major for the first time since 2006 but a double-bogey seven at the last saw her drop away to three under par.
Sweden's Anna Nordqvist tied for 10th and was the highest-placed European on one-under following a 71, while Karen Stupples was the leading Briton after a 78 dropped her to a share of 29th, four over par for the week.