Mugen driver Nojiri lost the lead to Toshiki Oyu at the start, but regained control of the race on lap 10 of 41 and led the remainder of the distance to secure a fourth career victory.
Oyu lost out by just 1.5s in the final reckoning, while Nirei Fukuzumi completed an all-Honda podium in third place ahead of the lead Toyota runner, Ryo Hirakawa.
Defending champion Naoki Yamamoto battled his way up to sixth place from 16th on the grid.
The forecast rain never quite arrived despite the cloudy and breezy conditions, with spots falling in the final 10 or so laps but never heavy enough to warrant a switch to wet tyres.
Nakajima Racing driver Oyu made a strong start from second on the grid to immediately seize the initiative from Nojiri, and was 2.4s to the good at the end of lap two.
But Nojiri steadily reeled in his younger rival thereafter, and retook the advantage with a bold outside move around Turn 10.
From there Nojiri steadily built up his lead, and was 3.7s clear at the halfway point as Oyu was forced to turn his attention towards defending from Fukuzumi’s Dandelion Racing machine.
Fukuzumi passed Oyu for second on lap 24, with Oyu becoming the first of the frontrunners to pit the next time by after losing a further position to Ukyo Sasahara (Dandelion).
Nojiri continued to extend his lead all the while, with his advantage peaking at around nine seconds once both Fukuzumi and Sasahara had served their mandatory stops.
With the threat of rain still looming, Nojiri and Hirakawa – now up to second – opted to leave their stops to virtually the last moment, with Hirakawa bringing in his Impul car on lap 38 and Nojiri finally pitting from the lead on the antepenultimate lap.
Oyu’s earlier stop had allowed him to leapfrog back ahead of Fukuzumi, and was 3.8s shy of Nojiri heading into the final lap, and setting the fastest lap of the race at the very end he missed out on a second career win by just 1.5s at the chequered flag.
Hirakawa emerged in fourth after pitting, splitting the Dandelion drivers as Sasahara was delayed by a slow stop and then by a late battle with Yamamoto (Nakajima Racing).
From 16th on the grid, Yamamoto gained eight positions in the first two laps and was the first driver to clear his mandatory stop on lap 10.
But a slow stop stymied his progress and he had to settle for sixth in the final reckoning ahead of TOM’S rookie Ritomo Miyata and Yuji Kunimoto in the best of the KCMG cars.
Sena Sakaguchi (Inging) and Kazuya Oshima (Rookie Racing) completed the top 10.
Tatiana Calderon missed out on scoring her first Super Formula points as she slipped from 11th on the grid to 13th, behind Kazuki Nakajima (TOM’S) and Kenta Yamashita (Kondo Racing).
Nakajima lost ground on the opening lap as he went off track to avoid a slowing Yuhi Sekiguchi (Impul), who suffered a puncture after first-lap contact with Hiroki Otsu (Mugen). The Red Bull-branded car of Otsu also sustained front wing damage, resulting in an early stop.
Sho Tsuboi (Inging) was on course for a top-six result when he crashed out with five laps to go.