Consigned to 15th on the GT500 grid after Matsuda’s heavy crash in qualifying, the fortunes of the #23 crew were transformed by a mid-race safety car period that was deployed just after Quintarelli had pitted to hand over to Matsuda.
Quintarelli had been running in 11th place at the start of the pitstop phase, but was one of the last two drivers to make his mandatory stop, doing so on lap 22 of 52.
Just moments later, the safety car was called following contact between the #3 NDDP/B-Max Nissan and the Saitama Toyopet Toyota GR Supra GT300 that left the latter car in the barriers – slowing down the field and sensationally allowing Matsuda to rejoin in the lead.
When the race resumed on lap 27, Matsuda was faced with pressure from Impul Nissan man Kazuki Hiramine, who inherited what appeared to be a net lead during the pitstop phase just a couple of laps prior from teammate Daiki Sasaki.
Hiramine stuck close to Matsuda initially and came close to making a pass exiting the final chicane on lap 35, but Matsuda clung on to the lead and as the race entered its closing stages he was able to build a small margin, finally pulling almost five seconds clear.
Ronnie Quintarelli, Tsugio Matsuda（#23 MOTUL AUTECH GT-R）
A late charge by the pole-sitting #8 ARTA Honda of Nirei Fukuzumi almost yielded second place, but Hiramine hung on to seal a Nissan one-two and Impul’s first podium since last year’s Okayama opener, and forcing Fukuzumi and his ARTA teammate Tomoki Nojiri to be content with third for a second race in a row.
Nojiri led for the first 19 laps before making his stop, but the ARTA car was jumped by not only Sasaki in the Impul machine but also the #3 Nissan and the #64 Nakajima Racing Honda when that trio of cars pitted on lap 20.
Fukuzumi was able to repass the #64 Honda and #3 Nissan, but was unable to find a way by Hiramine before the safety car period, and when the race resumed he was forced to focus on keeping Katsumasa Chiyo in the #3 Nissan at bay before catching up to Hiramine.
Fourth place for Chiyo and Kohei Hirate represented their best finish of the season, while a tightly-bunched top five was completed by Hiroaki Ishiura and Yuji Tachikawa in the best of the Toyota contingent, the #38 Cerumo GR Supra.
TOM’S Toyota duo Sacha Fenestraz and Yuhi Sekiguchi clawed back some vital ground in the championship fight with seventh, one place behind the Dunlop-shod Nakajima Honda of Hiroki Otsu and Takuya Izawa that had started on the front row.
The second TOM’S GR Supra of Nick Cassidy and Ryo Hirakawa however retired following an apparent collision with the #100 Kunimitsu Honda that was not caught on camera.
Rear-left damage on the Honda of Tadasuke Makino and a damaged nose for Cassidy's Toyota told the tale of a clash that spelt the end for the #37 crew, with Ryo Hirakawa soldiering on for some laps and serving a drive-through penalty before parking up the stricken Supra.
Naoki Yamamoto rejoined with a fresh, unpainted rear section on the Kunimitsu Honda, albeit some 20 laps down, finishing 14th.
Jann Mardenborough and Mitsunori Takaboshi led the Yokohama contingent in eighth in the Kondo Racing Nissan for only their second points finish of the year, followed by the Bandoh Toyota of Yuji Kunimoto and Ritomo Miyata that was delayed by a puncture.
Real Racing Honda pair Koudai Tsukakoshi and Bertrand Baguette salvaged a solitary point in 10th thanks to a late pass by Tsukakoshi on the struggling SARD Toyota that Yuichi Nakayama took over from Heikki Kovalainen.
The #14 Cerumo Toyota of Sho Tsuboi and Kazuya Oshima failed to score as Oshima pitted a lap too soon to hand over to Tsuboi, forcing the team into a second driver change in the latter stages that consigned the pair to 12th.
That leaves the top five cars in the standings separated by just two points, with Cerumo pair Tsuboi and Oshima still leading Cassidy and Hirakawa by one point, with Baguette/Tsukakoshi, Fenestraz/Sekiguchi and Quintarelli/Matsuda all a further point back.
GT300: Hitotsuyama Audi ends four-year losing streak
In GT300, the Hitotsuyama Audi squad came through for its first win since 2016 thanks to Shintaro Kawabata and Tsubasa Kondo.
#21 Hitotsuyama Audi R8 LMS
The mid-race caution had an even bigger impact on the secondary class than it did the main race, as the Hitotsuyama Audi R8 LMS was one of a handful of cars that had already pitted when the safety car came out - vaulting the car up to a net second.
Inheriting the net lead was the Inging Motorsports Toyota 86 MC of Ryohei Sakaguchi and Kazuko Kotaka, but Kotaka couldn't hold off Kawabata during their fight, although he managed to hang on for the new-for-2020 operation's first podium finish.
Also scoring a first top-three of the season were Goodsmile Racing pairing Nobuteru Taniguchi and Tetsuya Kataoka in their Mercedes-AMG GT3, as Taniguchi passed the Team Mach Toyota 86 MC to claim the final spot on the podium.
The pole-winning K-Tunes Lexus RC F GT3 had a difficult first stint in the hands of Morio Nitta, sliding down the order, but the safety car helped Nitta and Sena Sakaguchi salvage fifth.
The best of the five cars carrying maximum success ballast was the ARTA Honda NSX GT3 of Shinichi Takagi and Toshiki Oyu in seventh, followed by the LEON Racing Mercedes of Naoya Gamou and Togo Suganami in 10th place.
Subaru's works BRZ had led the opening stint but was one of the cars caught out by the safety car, leaving Takuto Iguchi and Hideki Yamauchi down in 12th at the finish.
With the #11 Gainer Nissan that was second in the points also failing to score for the same reason as the Subaru, it gives LEON pair Gamou and Suganami an enhanced 10-point lead at the top of the standings.
GT500 race results:
Real Racing Honda