CARLSBAD, 30 Mar 2015 (AFP) - The 37-year-old American made nine birdies, including four in a row from the 13th through 16th holes, to finish 72 holes on a tournament-record 20-under-par 268 for her first LPGA victory since the Kingsmill Championship 22 months ago.
"I just found something," Kerr said. "I'm really happy right now."
A tearful Kerr had vowed to win after her caddie, Greg Johnston, mourned the death of his father last week.
"I played for both of us this week," she said. "I said I was going to do it and I did it. Golf has always given me special moments like this and I'm grateful for it."
Lee was second, undone by a double bogey at 17, with world number one Lydia Ko of New Zealand third on 271, American Alison Lee fourth on 272 and South Korean world number two Park In-Bee fifth on 273.
Ko, 17, fired a 67, stretching her streak of sub-par rounds to 28 as she prepares for the year's first major tournament, next week's Ana Inspiration at Rancho Mirage.
"I made a lot of good putts," Ko said. "I wasn't hitting it in close but when I had the chance I made it. A 67 here is good and I improved my place from last year, so it's good and I'm ready for the first major next week."
Ko hopes to add her first major title to the Australian and New Zealand Open crowns she won earlier this year.
"The spotlight is on me. It's going to be a tough week," Ko said. "I've got to bring my A-game. Hopefully I'll hit some great shots and make some good putts."
Kerr took the $255,000 top prize some 43 starts after her prior LPGA triumph, overcoming a three-shot deficit to Kim with a sizzling round.
Kerr began a run of five birdies in six holes at the par-5 fifth and ended it at the par-5 10th. After stumbling with a bogey at 12, she ran off her longest birdie streak to seize the lead.
Her edge grew to three strokes when Kim made a double bogey at 17 and even though Kerr took a bogey at 18, Kim could not hole her approach for an eagle to force a playoff.