South Korea's I.J. Jang saw his overnight lead trimmed to two strokes after carding an even par 72 in the second round of the Mynavi ABC Championship on Friday.
Jang, who led by three strokes after a sizzling 63 on Thursday, had an up-and-down round that included three birdies, one bogey and one double bogey, but stayed top at 9-under 135 at ABC Golf Club.
Seeking his first win in Japan since capturing his maiden title at the 2005 Mitsubishi Diamond Cup, Jang stands two shots clear of compatriot and current money rankings leader Kim Kyung Tae and Azuma Yano, who had rounds of 70 and 69, respectively.
Defending champion Toru Suzuki carded a 70 and was alone in fourth at 6 under, followed in fifth by Komei Oda, who also shot a 70.
Ryo Ishikawa moved up to a share of eighth, a 71 leaving the teen star at 3 under, but last week's Bridgestone Open winner Yuta Ikeda (73) slid into a tie for 26th at even par.
Hattori, Campbell tied
HANNO , Saitama Pref. (Kyodo) Mayu Hattori and Australian Nikki Campbell shot 4-under 68s to share the first-round lead at the Hisako Higuchi Ladies on Friday.
Hattori and Campbell, both two-time winners on the JLPGA Tour, each had five birdies and a bogey at Musashigaoka Golf Course.
Akane Iijima and Hiromi Mogi were one stroke behind the leaders.
Sakura Yokomine, who has cut Ahn Sun Ju's lead in the money title race to about ¥33 million with last week's Masters GC Ladies victory, opened with a 71 to stand in a tie for 13th.
South Korean Ahn is sitting out this fifth-to-last event of the season.