The #23 NISMO Nissan Z of Matsuda and the #87 JLOC Lamborghini Huracan GT3 of Matsuura were caught up in a frightening accident at 130R that brought out the red flags on lap 59 of 77.
Both Matsuda and Matsuura were reported to be conscious and ok, with Matsuda being transferred to hospital by helicopter for further examination.
No replay of the accident was shown on TV, nor were images of the crash site shown.
Some time after the accident, it was announced that the race would not be resumed, with the 75 per cent threshold required for full points to be awarded having been reached.
However, there was confusion as to which GT500 car would be awarded the win, as the race-leading #3 NDDP Racing Nissan of Katsumasa Chiyo and Mitsunori Takaboshi had yet to complete its second mandatory refuelling stop.
The remainder of the GT500 cars had completed both stops, with Yuji Kunimoto and Sena Sakaguchi's #19 Racing Project Bandoh Toyota GR Supra running second ahead of the #36 TOM'S Toyota.
Had the #3 Nissan been given a penalty for not completing its second stop, it would have meant a first win since 2016 for the Bandoh car.
But the GT500 results were provisionally announced with the NDDP Nissan awarded the victory by 31.782 seconds ahead of the Bandoh Toyota.
The #36 TOM'S Toyota of Sho Tsuboi and Ritomo Miyata was classified third ahead of the Impul Nissan of Bertrand Baguette and Kazuki Hiramine in fourth and the Team Kunimitsu Honda NSX-GT of Tadasuke Makino and Naoki Yamamoto in fifth.
Leading the way in the GT300 class prior to the stoppage was the #7 Team Studie BMW M4 GT3 of Seiji Ara and Masataka Yanagida.
The pair were confirmed as the winners ahead of the Inging Toyota GR86 of Hibiki Taira and Yuui Tsutsumi, with the Saitama Toyopet Toyota GR Supra of Kohta Kawaai and Hiroki Yoshida third.
