Cherry Hills Village, Colo. ? The confident pursuit of a Grand Slam gave way to frustration as Annika Sorenstam tried to make up ground and instead went backward in the U.S. Women’s Open.

First came a tee shot into the rough and a dubious decision to go for the green. That was followed by another bad tee shot into rough so deep she had to lay up twice on the par-5 17th. Her shocking finish ended with a conservative play off the 18th tee, leaving her a 4-wood up the hill toward the green.

Three holes. Three bogeys.

When the damage was done, Sorenstam found herself six shots behind Nicole Perrot of Chile, a surprising leader on a Friday filled with wild swings of momentum.

“Sometimes you just can’t analyze things,” Sorenstam said after a 4-over 75. “You’ve got to drop it and move on.”

Perrot, a 21-year-old from a country of just 58 private golf courses, shot her second straight round of 1-under 70 by saving par with a 10-foot putt on the 14th and staying clear of trouble down the stretch. At 2-under 140, she was the only player under par after two rounds at Cherry Hills.

The final group will not be without some star power.

While Sorenstam showed she was not invincible, 15-year-old Michelle Wie came of age by salvaging pars in a scrappy round for a 1-over 73 that left her at 142 and in the final pairing with Perrot.

“I could have shot some ridiculous numbers today, but I kept my head, and I made a couple of good par putts, and I think that kept me going,” Wie said.

Lorena Ochoa, who didn’t make a par on the back nine until the 17th hole, closed with a bogey for a 3-under 68 and joined Wie at 142. Rachel Hetherington (69), Angela Stanford (74) and 18-year-old Paula Creamer (69) were another shot behind.