After starting on the 10th, 31-year-old Pettersen picked up four birdies over her first seven holes to put herself in the driving seat at Blackwolf Run in Kohler, Wisconsin.
She finished the day five under overall after signing for a four-under 68 - one stroke ahead of American duo Wie and Cristie Kerr.
"I played pretty good today [Friday]," Pettersen said. "I got off to a very good start, hit a lot of the shots I tried to hit, and just tried to execute my game plan.
"The course is very playable. You hit the fairways, you give yourself a lot of chances out here. Greens are rolling perfect."
Wie had started with a disappointing 74 on Thursday but got her bid firmly on track with a stunning 66, while 2007 champion Kerr - who was in a three-way tie for the lead after the first round - posted a score of 71.
"I felt pretty good today [Friday]," said 22-year-old Wie, who collected seven birdies in a round spoiled only by a bogey six on the second. "It was a really good confidence boost for the weekend. I'm just going to build on it.
"I'm pretty stoked to be back in contention and honestly not have to worry about the cut line."
Germany's Sandra Gal, South Korea's Inbee Park and American Vicky Hurst were a further shot back on three under after following up their opening 71s with rounds of 70 on Friday.
Americans Lizette Salas and Brittany Lincicome, joint first-round leaders alongside Kerr, carded 73 and 80, respectively.