The trophy seems certain to remain in home hands after the international challenge - including Australia's - faltered on moving day at the LPGA Tour's $3.2 million Toto Japan Classic.
Headed up by halfway co-leader Nasa Hataoka, Japanese players hold down the top six positions after the third round at Seta Golf Club in Shiga.
Hataoka retains a share of the lead following a second straight four-under-par 68, with Yuna Araki joining her in front after carding a brilliant 65 on Saturday.