Ayako Uehara shot a 1-under 71 to fall back to fourth place Friday after the second round of the ANA Inspiration, the first of the year's five women's majors.
Overnight leader Pernilla Lindberg of Sweden was joined by South Korea's Park Sung-hyun atop the leaderboard with both players at a 36-hole tournament record 12-under 132. Park's Friday 64 was the day's best round at Mission Hills Country Club.
"I had many chances early on but I wasn't able to make my short putts," said Uehara. "It's good that I finished under par. The gap to the leaders widened but I'm in a good position."
Uehara, one of four Japanese taking part in the $2.8 million tournament, will head into the weekend with a chance to become the first Japanese woman to win a major since Hisako Higuchi claimed the LPGA championship in 1977.
American Jessica Korda has sole possession of third, three shots behind the joint leaders, while Uehara and three others are a further two shots back at the tournament halfway point.
Uehara, who was tied for second after her opening-round 66, had three birdies against two bogeys.
Nasa Hataoka and Ai Suzuki, the latter the money leader on the Japan LPGA tour last season, both shot 73s to sit 1-under and 1-over, respectively.