Joint overnight leader Yuki Inamori delivered a solid second-round four-under-par 67, establishing a two-shot lead at the halfway stage of the Yokohama Minato Championship - Fujiki Centennial in Kanagawa.
Chasing his fifth JGTO victory, the 28-year-old sunk six birdies against two bogeys at the Yokohama Country Club on Friday, reaching the 36-hole mark on 10-under-par 132.
Fellow early starter Taisei Shimizu was among the closest challengers alongside Ryo Katsumata, as he shined with a remarkable 61 to leap 78 places into a tie for second on eight-under.
Shimizu kept the bogeys at bay as he lit up the course with 10 birdies, while Katsumata marked his scorecard with an eagle, four birdies, and two bogeys for a second consecutive 67s.
Inamori attributed his good run so far to his affinity for the course.
The Yokohama Country Club certainly holds a special place for him as it was where he won the Japan Open for his career breakthrough title in 2018.
"I have an emotional attachment, and I've been here a few times in private, so I think I have somewhat grasped the feel of the place," said Inamori, who last claimed a title at the Japan Players Championship last year.
Despite the two-shot cushion and the edge he has at his favourite hunting ground, Inamori is not taking anything for granted.
"I can't let my guard down. Although the fairways are wide, precision is required for the second shot. The greens also have strong undulations, hence even a slight miss makes the approach shots tricky.
"I personally find the inward holes harder (he had bogeys on 16 and 18), so I want to reset my mind and do my best tomorrow."
Shimizu, who opened with a disappointing 73, has pledged to continue attacking the pin over the weekend, as he believes an aggressive approach can be rewarding on this course.
"It's a course where you can increase your chances of opportunities if you attack," said Shimizu, who's in his third season on the JGTO.
"Today, I decided to play aggressively rather than focusing too much on protecting my score.
"I've been in decent form recently. However, even when I started strong, I typically ended up around four-under.
"So, it was great to score significantly for the first time in a while.
"I want to play good golf every day for the next two days without overthinking. If I play good golf, the results will naturally follow.
Veteran Tadahiro Takayama, who shared the first-round lead with Inamori, failed to build on his good start, which included an eagle on the par-five fourth hole. He squandered the two-stroke advantage almost immediately with a double bogey on the sixth hole.
Takayama then dropped another shot at the 16th, finishing with a 72, which resulted in him slipping to joint seventh on five-under with two others including Australia's Adam Bland.
Bland traded seven birdies against three bogeys to sign for a 67, placing him as the best international finisher after two days.
Leading second round scores:
132: Yuki Inamori 65-67;
134: Ryo Katsumata 67-67, Taisei Shimizu 73-61;
135: Yu Morimoto 69-66;
136: Kosuke Suzuki 69-67, Yuwa Kosaihira 67-69;
137: Terumichi Kakazu 72-65, Tadahiro Takayama 65-72, Adam Bland (Aus) 70-67;
138: Ryutaro Nagano 72-66, Lee Sang-hee (Kor) 68-70, Dylan Perry (Aus) 69-69, Keita Nakajima 69-69, Kazuya Koura 66-72, Eric Sugimoto 68-70, Taiga Semikawa 71-67, Yuta Uetake 70-68, Kenta Endo 66-72.