Jutanugarn, 17, will be seeking Sunday to become the second teenager to win a professional women's tournament this year. Lydia Ko, 15, won the ISPS Handa New Zealand Women's Open two weeks ago.
Jutanugarn had a very uneven round Saturday, however. She had seven birdies but also a double bogey and bogeys on three of her final four holes in a 2-under-par 70 and 54-hole total of 11-under 205.
Stacy Lewis, who led by three strokes going into the third round, suffered through a six-bogey day -- including bogeys on her last three holes -- for a 4-over 76. She is tied with Pak Se-ri (71 Saturday) and Beatriz Recari (70) for second at 8-under.
Jutanugarn opened her third round with a birdie but, after seven pars, had a double bogey at the par-4 ninth. She ran off five straight birdies over Nos. 10-14 in taking the lead. She went bogey-birdie at Nos. 15 and 16 before bogeys at 17 and 18 brought her closer to the field.