Round 4 of the 2023 SUPER GT was held at Fuji Speedway on August 5th and 6th.
In the qualifying round held under clear skies, Tsukakoshi took on Q1 and got the checkered flag in 8th, narrowly advancing to Q2 for the third consecutive round.
The final 450-km race started in the rain, in contrast to the qualifiers. Matsushita moved up to 4th in the opening lap, but the team incurred a drive-through penalty for failure to follow the starting procedure, which dropped the team to 14th. However, he unrelentingly pursued the machines out in front, and closed the gap with the Safety Car emerging due to machine trouble in the GT300 class. After restart, he further improved his pace and moved up to 11th, and the team switched drivers to Tsukakoshi with pit stop on lap 57.
Tsukakoshi gradually improved the pace to in on the group battling for 3rd, but the race saw another red flag due to machine trouble in the GT300 class. The rain intensified, forcing the race to be restarted one hour before the end of the race. Tsukakoshi closed the gap to the front and finally moved up to 3rd with 14 laps to go. However, as the tarmac started to dry he was unable to improve his pace and rivals overtook him for an eventual 7th place finish.