Kensei Hirata soared into the lead after firing a flawless nine-under-par 61 in the second round of the Kansai Open Golf Championship on Friday.
Starting the day trailing by four shots, the 23-year-old notched up nine birdies, six of which came in the last eight holes, to establish a slender one-shot lead with a nine-under 131 total at Meishin Yokaichi Country Club in Shiga Prefecture.
Joint overnight leader Taisei Shimizu shot a second successive 66 to finish in sole second place, while Takahiro Hataji was the other big mover of the day, sparkling with a 65 to climb from T17 to third with a 134 total.
American Todd Baek birdied all four of his final holes, finishing as the best-placed international player at the halfway point.
He carded a solid 66 to be tied for fourth with a 135 total.
Following a standout season last year, Hirata has struggled to replicate the form that saw him win two titles – the Gateway to The Open Mizuno Open and the Japan PGA Championship.
Now in his third full season, Hirata's best outing this year has been a T12 finish at The Crowns two weeks ago.
The last time he topped the leaderboard was at the Japan PGA Championship in July last year, where he secured a wire-to-wire victory.
Meanwhile, Michael Hendry of New Zealand put himself on the fringe of contention after carding a much-improved 67 to add to his opening 72.
Despite a rough start on the front nine, where he dropped four bogeys and managed only a single birdie, Hendry staged a remarkable comeback on the back nine with an eagle, five birdies, and just one bogey.
The valiant fightback lifted Hendry from the brink of missing the cut to T26 with a 139 total.
At eight shots off the pace, Hendry's bid for back-to-back wins, following last week's triumph at For The Players by The Players, remains very much alive.
Leading second round scores:
131: Kensei Hirata 70-61;
132: Taisei Shimizu 66-66;
134: Takahiro Hataji 69-65;
135: Shinichi Yokota 67-68, Taisei Sato 66-69, Todd Baek (US) 69-66, Tomoyasu Sugiyama 67-68;
136: Tomohiro Ishizaka 68-68, Atomu Shigenaga 69-67, Shingo Katayama 68-68, Yuta Sugiura 68-68; Osei Tada (am) 69-67, Shintaro Kobayashi 67-69, Shugo Imahira 71-65, Terumiuchi Kakazu 69-67.