That followed up her first-round, one-over-par 73 at Mission Hills Country Club in Rancho Mirage and left the reigning British Open champion on 147, ten shots off the pace set by Kim Song-hee.
The 21-year-old South Korean stole the limelight from some of the biggest names on the LPGA Tour by taking a one-shot lead.
In pursuit of her first title on the US women's circuit, Kim fired a flawless four-under-par 68 to end a tough day for scoring at Mission Hills Country Club at seven-under 137.
She held a one-stroke advantage over major winners Cristie Kerr, Lorena Ochoa and veteran Briton Karen Stupples.
American Kerr eagled the par-five 11th on her way to a best-of-the-day 67.
Mexican world number one Ochoa returned a 70 and Stupples carded a 69.
Twice champion Karrie Webb of Australia shot a 70 to share fifth place at five under with American Stacy Lewis (68) on a high-quality leaderboard.
"I had a great round and my swing was really smooth and comfortable," said Kim. "Also I had great putting today. Everything was good."
The cut fell at six over with Japan's Ai Miyazato, a double winner on the 2010 LPGA Tour, and American Natalie Gulbis among those missing out.