Sakura Yokomine slid down the leaderboard after struggling to a 3-over-par 75 in the second round of the LPGA Volvik Championship on Friday.
Yokomine started the day five shots off the lead and tied for sixth place, but a round of three birdies, four bogeys and a double bogey on the 12th hole at Travis Pointe Country Club in Ann Arbor, Michigan, saw her drop into a share of 45th at even-par 144.
"It was disappointing that I three-putted (for bogeys) twice in the first half of my round," said Yokomine. "I could not get a rhythm going.
"My shots were in an acceptable range. I have to work mainly on my putting for the third round," she said.
Thailand's Ariya Jutanugarn shot a 4-under 68 and will enter the weekend with a two-shot lead that keeps her on course for a third consecutive victory on the LPGA Tour.
Ariya had another bogey-free round but said enjoying her golf was on her mind more than becoming the first player to win three titles in a row since South Korea's Park In-bee in 2013.
"Right now I'm really happy with it and really enjoy playing golf, so I'm not thinking about (whether) I'm going to win or I'm going to lose, but just have fun and keep playing well," she said.
Overnight leader Christina Kim (71), fellow American Marina Alex (67) and South Korea's Ryu So-yeon (67) shared second place.
Elsewhere for Japan, Ayako Uehara shot a 70 and moved up to a tie for 27th place at 2 under, but former world No. 1 Ai Miyazato shot 74 and missed the cut.
