California:Only nine players finished under par on Friday during another tough day at Mission Hills, as the course for the first LPGA Tour major of the year continued to play firm and fast.
Ochoa bounced back from a double bogey on the par-four 15th hole with two consecutive birdies on 17 and 18. The 25 year old, who won six times on the LPGA Tour in 2006, is threatening to replace Sorenstam at the top of the world rankings.
She hit five birdies on Friday and carded a one-under 71 for the round, four-under par for the tournament.
Shi Hyun Ahn, playing in the final group of the afternoon reached five-under par for the tournament with a birdie on the 11th hole, but four bogeys, and a double bogey amongst a couple of birdies saw her return a round of one-over-par 73.
Ahn will start the third round at three-under par for the championship.
Joining Ahn at three-under was Pettersen, a runner-up to Ochoa last week at the Safeway International in Phoenix. Her steady round of 69 was comprised of four birdies including this long putt and a single bogey.
Scotland's Catriona Matthew judged this downhill putt to perfection and was among a group of four players at one-under par while Se Ri Pak, who needs a win at Rancho Mirage to complete the career grand slam, was one stroke ahead at two-under par.
Juli Inkster found something to celebrate at the end of her round, holing this monster putt from the fringe for birdie on the 18th hole.
She stands at six-over par, safely inside the cut of nine-over par. The day's marquee pairing saw Sorenstam play alongside Creamer, though their fortunes could hardly have been more different.
Sorenstam's misses this par putt on the 13th and finished four-over par for the round and left her on seven-over par for the tournament, her highest 36-hole start at a major since she playing the 1992 US Women's Open as an amateur.
However Creamer, was all class and approach shots like this in the tenth, helped her post a bogey-free round of 67.
Her tee shot on the 14th summed up her near perfect round, the only thing that did let her down on occasions was her putter as she missed four birdie putts inside 12 feet, but she is tied for the lead heading into the weekend.