South Korean tour veteran Ko Woo Soon shot a 3-under-par 70 in difficult conditions Saturday and will take a one-stroke advantage into the final round of the New Caterpillar Mitsubishi Ladies.
Ko made three birdies in a bogey-free round on a blustery, overcast day, leapfrogging eight players into the lead with a 3-under 143 total.
The 38-year-old from Pusan, who has won six Japan LPGA tour events, birdied the opening hole and added back-to-back birdies from No. 15 after a string of par saves kept her game alive on a day when only four players broke par.
"I fell into trouble several times but just tried to keep my patience. It looks like it paid off and led to such a solid round," Ko said.
Ko maintained the form that helped her finish tied for second behind Akiko Fukushima following three consecutive sub-70 rounds at last week's NEC Karuizawa 72 tournament.
Kaori Higo closed within one shot of the pace with her second straight 72 on a par-73 layout as the 2000 Japan Women's Open champion aims for her first victory of the year.
Nobuko Kizawa (74) sits another stroke back at 1-under 145, followed by Midori Yoneyama (73) and first-round leader Wei Yun-jye of Taiwan (76) at 146.