For the second straight day Pettersen came within a shot of equaling the low score of the round and her 36-hole total of 134 put her one ahead of Ai Miyazato.
Blustery winds kicked up Thursday to make birdies harder to come by at the Ko Olina Golf Club course.
Ariya Jutanugarn turned in a 64 for Wednesday's low score, but the best anyone could do Thursday were the 68s turned in by Miyazato and Jodi Ewart Shadoff.
Michelle Wie barely survived the cut at 146 and will start the third round in a tie for 68th place.
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