Beatriz Recari carded a steady 3-under 69 on Saturday to hang on to the top spot at the Kia Classic.
Recari, whose lone LPGA victory came at the 2010 CVS/pharmacy LPGA Challenge, finished three rounds at Aviara Golf Club at 11-under-par 205.
"The last time I was in the lead heading into the fourth round was when I won, so it feels good," said Recari.
Karrie Webb stumbled to a pair of bogeys over her last two holes en route to a 2-under 70 to fall into sole possession of second place at 9-under-par 207, while Paula Creamer (71) and I.K. Kim (70) shared third place at minus-8.
Newly-crowned world No. 1 Stacy Lewis finished her third round with a 3-under 69 to move into a tie for fifth with Lizette Salas (70) and Cristie Kerr (71) at 7-under.
Recari entered Saturday holding a 1-stroke lead over Webb and Creamer, but Recari parred her first 10 holes to allow Webb to move to the top of the leaderboard.
Webb countered a bogey at the second with five birdies over the next 10 holes to move to 11-under for the tournament and take a 2-stroke lead over Recari following the Spaniard's birdie at the 11th.
Webb dropped a stroke with a a bogey at the 13th, but drove her tee shot on to the green at the par-4 16th and 2-putted for birdie to regain her cushion.
Recari, however, also drove on to the green at the 16th with the next group and converted her eagle putt to grab a share of first place.
Webb then hit her tee shot at the 17th into a group of trees to the right of the fairway, resulting in a bogey to allow Recari to regain the lead.
Webb was then well short of a lengthy par attempt and 2-putted for bogey at the last after scrambling out of a bunker to fall two strokes behind Recari, who closed her round with a pair of pars.
"Not every time that I give myself a chance to win do I win, but that's where I feel the most comfortable," Webb said. "I like to have a chance to win and I've put myself in there with a good shot tomorrow. Because of my experience, I'm comfortable there."
Creamer traded three birdies with two bogeys over her first nine holes to hit the turn at 8-under, and then poured in another birdie at the 11th.
But after parring the next six holes, Creamer bogeyed the last to fall three strokes off the pace.
NOTES: Webb has 38 career LPGA victories, but her most recent win was at the 2011 RR Donnelley LPGA Founders Cup ... Recari has not recorded a bogey in any of her three rounds this week.