A second round 72 means Olivia Mehaffey advances to the historic final round at the inaugural Augusta National Women's Amateur, but Jennifer Kupucho remains top of the leaderboard.
Kupcho's bogey-free run finally came to an end, but the American hung on for a one-stroke lead after the second round.
Belfast native Mehaffey went one better than her opening round 73 and tied for 11th place, safely made the cut.
The former Curtis Cup player sits six shots off the lead following a mixed round, which saw Mehaffey card four birdies and four bogeys in her level-par round.
Only the top 30 players after two rounds advanced to the final round, when they will become the first women to compete at the home of the Masters, but all 72 players in the field can play a practice round at Augusta National on Friday.
Kupcho, the world's top-ranked amateur, shot a one-under par 71 at Champions Retreat Golf Club in Evans, Georgia, leaving her at five under on the week going into the final round on Saturday at Augusta National Golf Club ahead of next week's Masters.
Kupucho, fresh off what she called her first "perfect" round, started on the back nine and was cruising along at three-under for the day until her 14th hole, the par-four fifth, where she made her first bogey of the week.
The 21-year-old then made bogey at her penultimate hole before a par at the last left the overnight co-leader one shot clear of Mexico's Maria Fassi (70), whose roller-coaster round included five bogeys, five birdies and an eagle.
Thailand's Pimnipa Panthong (70) and Americans Sierra Brooks (70) and Kaitlyn Papp (69) were a further shot off the pace.
American Zoe Campos, who at 16 is one of the youngest players in the field, started the day in a share of the lead but mixed six bogeys with three birdies for a three-over 75 that left her four shots behind Kupcho.