Ryosuke Kinoshita shot a second-round six-under-par 66 to join Mikumu Horikawa at the top of the leaderboard of the Gateway to The Open Mizuno Open in Okayama.
The 32-year-old Kinoshita followed his opening 69 with an impressive bogey-free round featuring six birdies at the JFE Setonaikai Golf Club on Friday, reaching the halfway stage at nine-under 135.
Horikawa battled to a 71 after trading four birdies against three bogeys, including two consecutive dropped shots on 13 and 14, but it was still good enough to retain his place at the summit.
Tomoyo Ikemura and Mikiya Akutsu, the joint overnight leaders, carded 69 and 73 respectively to share third place at 137.
Defending champion Kensei Hirata also scrambled to salvage a 72 to sit a further one shot back in fifth and was joined by Yuto Katsuragawa (69) and 2019 winner Yuta Ikeda (69) in fifth place.
Kinoshita, a two-time JGTO winner, was pleased to have put an end to a two-tournament streak of missed cuts, doing so in style, which further fuels his desire to break a title drought since 2021.
"Since I haven't won in three years, I'm filled with a strong desire to win as soon as possible," said Kinoshita.
More importantly, this good start also enhances his chances of qualifying for The Open Championship for the second time since 2021.
He was eager to make amends after narrowly missing out on a spot in the US Open through the one-day, 36-hole qualifier at the Hino Golf Club on Monday.
"I missed out on the US Open spot on Monday by just one shot. But I still have the British Open qualification to fight for, so I will try to bounce back," said Kinoshita.
"I always have the desire to play in high-level tournaments abroad. I believe I've learned and grown a lot from events like the British Open, the US Open, and the WGCs. My desire to compete in such tournaments is strong."
Horikawa remains upbeat despite struggling in the back nine and failing to extend his overnight advantage.
He lamented the decision to change the putter grip.
"The first half was good, but when I changed my grip on the putter halfway through, it didn't go so well," said Horikawa.
"It was good in practice, so I thought I'd give it a try, but it just didn't work out at all.
"It was tough out there with nobody making much headway in the afternoon.
"Even though it wasn't a golf round I'm satisfied with, I managed to finish at one-under. It's not too bad."
Shaun Norris of South Africa emerged as the best-placed international at the 36-hole mark after carding a 69, placing him tied for eighth at 139.
Leading second round scores:
135: Ryosuke Kinoshita 69-66, Mikumu Horikawa 64-71;
137: Tomoyo Ikemura 68-69, Mikiya Akutsu 64-73;
138: Kensei Hirata 66-72, Yuto Katsuragawa 69-69, Yuta Ikeda 69-69;
Takahiro Hataji 71-68, Taiga Nagano 68-71, Koumei Oda 69-70, Ryoma Iwai 67-72, Kazuki Higa 69-70, Kota Kaneko 67-72, Hideto Kokuburo 69-70.