Recari started the round one shot ahead, but looked likely to lose that lead to Australia's Karrie Webb as she came into the final three holes of her round trailing.
But a stunning drive on the 285-yard par-4 16th hole rolled up to four feet from the cup, and Recari calmly rolled in the putt for an eagle to regain control of the tournament, with Webb dropping back thanks to a bogey on the 17th.
Paula Creamer and I K Kim of South Korea are tied for third, a further shot back.
Newly-installed world number one Stacy Lewis, who is going for a third consecutive victory, had an eagle on the 8th on her way to a 69 to finish to finish tied fifth, four strokes off the lead and alongside Lizette Salas and Cristie Kerr.
Recari was delighted with her efforts, particularly on the 16th.
"I hit that tee shot in the practice round, actually in the pro-am, and you just had to kind of play it safe," Recari said. "And if you get a good bounce, you knew that it was going to bounce left.
"If you got a good bounce on the green, great, even though just to make sure that I'm on the right side and I have enough green to work with. But I hit a very good tee shot and I had a good bounce as well so I had like a (four-footer) for eagle and I made it.
"I had like two good saves today, but other than that I played really well, hitting the ball solid and just making sure that I position the ball in the right place."