Tsukakoshi, who shares the #17 Real Honda NSX-GT with Nobuharu Matsushita, came out on top in a pulsating battle with Toshiki Oyu in the closing stages of the 300km race following an earlier red flag.
That was due to Naoki Yamamoto suffering a major crash in the Kunimitsu Honda exiting the final corner after contact with the Kondo Racing Nissan GT300 car, which led to the race being paused for around 50 minutes.
Yamamoto was airlifted to hospital, where it was established he had suffered no serious injuries, according to Honda.
The pole-winning #8 ARTA Honda of Tomoki Nojiri and Oyu finished seven seconds in arrears of the Real NSX in second, just holding on ahead of the NISMO Nissan of Tsugio Matsuda and Ronnie Quintarelli.
Tsukakoshi and Matsushita now find themselves only a single point away from the lead of the standings, which is held by NDDP Nissan pair Katsumasa Chiyo and Mitsunori Takaboshi, with two races to go.
In GT300, Team UpGarage pair Takashi Kobayashi and Shun Koide scored a dramatic victory in their Honda NSX GT3 as the leading Saitama Toyopet Toyota GR Supra appeared to run out of fuel at the finish line.
Story of the race
Nojiri led the start of the race from pole in the #8 ARTA Honda, quickly building a cushion at the head of the field ahead of Quintarelli in the NISMO Nissan and Matsushita in the Real NSX.
By the end of lap 17, Nojiri's advantage was out to more than 12 seconds, but it was back down to less than 10 seconds by the time the pitstop phase began on lap 28 of 84.
The first of the three leaders to pit was Quintarelli, who came in to hand over to Matsuda on lap 30, while Nojiri stayed out until lap 32 and Matsushita enjoyed a single lap in the lead before pitting on lap 33.
But the Real crew gained a significant amount of time during the pitstops, with the result that Tsukakoshi was able to come out ahead of Oyu and maintain the lead even while he got his tyres up to temperature.
Meanwhile, the SARD Toyota of Yuhi Sekiguchi and the Impul Nissan of Bertrand Baguette cycled through to first and second by virtue of leaving their stops later, but neither had pitted by the time of Yamamoto's crash at the end of lap 39.
Sekiguchi led the field back to green as the race resumed on lap 45, but because the safety car had picked up the leader prior to the stoppage, it meant Tsukakoshi, Oyu and Matsuda were able to rejoin at the back of the queue and gain almost a whole lap on the field.
Tsukakoshi initially held firm but couldn't shake off Oyu, who was able to make use of lapped traffic to set up a move through the final corner and along the start/finish straight at the end of lap 52.
When Sekiguchi made his stop that lap, Oyu, Tsukakoshi and Matsuda retook the top three positions. Oyu built a three-second lead over Tsukakoshi, but appeared to start struggling as the race wore on, allowing both Tsukakoshi and Matsuda back into the frame.
Tsukakoshi was clearly the faster of the two Honda drivers in clear air, and at the end of lap 76 another moment with lapped traffic at the last corner gave him the chance he needed to repass Oyu for the lead.
From there, Tsukakoshi stretched a lead of seven seconds by the chequered flag to score he and Matsushita's first win of the season and their second as a duo following last year's Autopolis round.
Matsuda settled for third place behind Oyu, while the SARD Toyota GR Supra of Sekiguchi and Yuichi Nakayama was a distant fourth, a massive 58 seconds behind at the finish but having had the chance to make a pitstop while essentially a lap ahead of fifth place and back.
The Impul Nissan shared by Baguette and Kazuki Hiramine stopped on lap 44 as the safety car came in, Hiramine initially slipping down to the foot of the top 10 on cold tyres. But on fresher rubber, the #1 car was able to steadily claw back positions to complete the top five.
Kondo Racing pair Daiki Sasaki and Kohei Hirate made it three Nissan Zs in the top six, ahead of a trio of Toyota crews, with Rookie Racing leading home the #36 TOM'S and the Racing Project Bandoh GR Supras.
The championship-leading NDDP Nissan scored a single point in 10th to take Chiyo and Takaboshi's points tally for the year to 50, with Tsukakoshi and Matsushita on 49 and TOM'S pair Sho Tsuboi and Ritomo Miyata on 48.
ARTA's second car, the #16 NSX that won at Suzuka, was 13th after a technical issue that put it in the garage early on, but Nirei Fukuzumi and Hiroki Otsu remain fourth overall, 13 points behind the leaders.
GT300: UpGarage steals dramatic win from Saitama Toyopet
In the GT300 class, Honda squad Team UpGarage scored its third win of the season, putting drivers Takashi Kobayashi and Shun Koide into a commanding position in the title race.
Carrying 100kg of success ballast, Kobayashi looked on course to bring home the UpGarage Honda NSX GT3 second behind the Saitama Toyopet Toyota GR Supra of Hiroki Yoshida and Kohta Kawaai, which had jumped up the order during the pitstops after only changing two tyres.
But with the chequered flag in sight, Yoshida dramatically slowed as he appeared to run out of fuel, allowing Kobayashi to pass for the victory by just eight tenths of a second.
Kobayashi and Koide's third win of 2023 puts them 15 points clear in the title race ahead of Yoshida and Kawaai, and marks the first time any GT300 squad was won three times in one season since 2011.
Behind Yoshida and Kawaai, Shade Racing pair Katsuyuki Hiranaka and Eijiro Shimizu delivered the team's first podium finish in SUPER GT after having led the race until the pitstop phase in their Toyota GR86 GT.
Completing the top five were the Team LeMans Audi R8 LMS of Yoshiaki Katayama and Roberto Merhi and the works Subaru BRZ shared by Takuto Iguchi and Hideki Yamauchi, while the pole-sitting K-tunes Lexus RC F GT3 of Morio Nitta and Shinichi Takagi slumped to a disappointing ninth place.
Besides the UpGarage Honda, the three remaining crews carrying the maximum 100kg success ballast failed to score points.
The Inging Toyota GR86 of Hibiki Taira and Yuui Tsutsumi was an early retirement, while the Team Studie BMW M4 GT3 of Seiji Ara and Bruno Spengler finished 14th in its least competitive showing of the year.
But the Kondo Racing Nissan GT-R NISMO GT3 of Joao Paulo de Oliveira and Teppei Natori lost the chance of a big points haul after the contact with Yamamoto's Honda GT500 car, which appeared to take place as Natori pitted.
The #56 crew was handed a drive-through for the incident, and was called back into the pits as a result of de Oliveira being judged to have illegally touched his car's bodywork during the red flag period.
De Oliveira finally brought the car home 11th, with he and Natori now 22 points behind Kobayashi and Koide in the standings and two behind BMW man Ara.
GT500 results:
| Pos. | No. | Car | Drivers | Laps | Time/Diff | Tire | SW |
|---|---|---|---|---|---|---|---|
| 1 | 17 | Astemo NSX-GT | Koudai Tsukakoshi Nobuharu Matsushita |
84 | 2:24'23.893 | BS | 58 |
| 2 | 8 | ARTA MUGEN NSX-GT | Tomoki Nojiri Toshiki Oyu |
84 | 2:24'30.932 | BS | 22 |
| 3 | 23 | MOTUL AUTECH Z | Tsugio Matsuda Ronnie Quintarelli |
84 | 2:24'31.461 | MI | 50 |
| 4 | 39 | DENSO KOBELCO SARD GR Supra | Yuhi Sekiguchi Yuichi Nakayama |
84 | 2:25'22.590 | BS | 46 |
| 5 | 1 | MARELLI IMPUL Z | Kazuki Hiramine Bertrand Baguette |
84 | 2:25'26.625 | BS | 48 |
| 6 | 24 | REALIZE CORPORATION ADVAN Z | Daiki Sasaki Kohei Hirate |
84 | 2:25'33.411 | YH | 10 |
| 7 | 14 | ENEOS X PRIME GR Supra | Kazuya Oshima Kenta Yamashita |
83 | 2:24'27.039 | BS | 64 |
| 8 | 36 | au TOM'S GR Supra | Sho Tsuboi Ritomo Miyata |
83 | 2:24'32.586 | BS | 90 |
| 9 | 19 | WedsSport ADVAN GR Supra | Yuji Kunimoto Sena Sakaguchi |
83 | 2:24'32.852 | YH | 48 |
| 10 | 3 | Niterra MOTUL Z | Katsumasa Chiyo Mitsunori Takaboshi |
83 | 2:24'34.137 | MI | 98 |
| 11 | 37 | Deloitte TOM'S GR Supra | Ukyo Sasahara Giuliano Alesi |
83 | 2:24'35.254 | BS | 16 |
| 12 | 64 | Modulo NSX-GT | Takuya Izawa Kakunoshin Ota |
83 | 2:24'35.709 | DL | 38 |
| 13 | 16 | ARTA MUGEN NSX-GT | Nirei Fukuzumi Hiroki Otsu |
82 | 2:24'28.068 | BS | 74 |
| 14 | 100 | STANLEY NSX-GT | Naoki Yamamoto Tadasuke Makino |
37 | 1:17'23.008 | BS | 62 |
| 15 | 38 | ZENT CERUMO GR Supra | Yuji Tachikawa Hiroaki Ishiura |
35 | 46'02.030 | BS | 36 |
GT300 results:
| Pos. | No. | Car | Drivers | Laps | Time/Diff | Tire | SW |
|---|---|---|---|---|---|---|---|
| 1 | 18 | UPGARAGE NSX GT3 | Takashi Kobayashi Shun Koide |
79 | 2:25'46.245 | YH | 100 |
| 2 | 52 | SAITAMATOYOPET GB GR Supra GT | Hiroki Yoshida Kohta Kawaai |
79 | 2:25'47.096 | BS | 90 |
| 3 | 20 | SHADE RACING GR86 GT | Katsuyuki Hiranaka Eijiro Shimizu |
78 | 2:24'31.619 | DL | 3 |
| 4 | 6 | DOBOT Audi R8 LMS | Yoshiaki Katayama Roberto Merhi |
78 | 2:24'38.406 | YH | 45 |
| 5 | 61 | SUBARU BRZ R&D SPORT | Takuto Iguchi Hideki Yamauchi |
78 | 2:24'48.069 | DL | 69 |
| 6 | 4 | GOODSMILE HATSUNE MIKU AMG | Nobuteru Taniguchi Tatsuya Kataoka |
78 | 2:24'56.539 | YH | 27 |
| 7 | 65 | LEON PYRAMID AMG | Naoya Gamou Takuro Shinohara |
78 | 2:24'59.021 | BS | 72 |
| 8 | 50 | ANEST IWATA Racing RC F GT3 | Igor Fraga Yuga Furutani |
78 | 2:24'59.744 | YH | 3 |
| 9 | 96 | K-tunes RC F GT3 | Morio Nitta Shinichi Takagi |
78 | 2:25'14.206 | DL | 15 |
| 10 | 10 | PONOS GAINER GT-R | Hironobu Yasuda Riki Okusa |
78 | 2:25'16.445 | DL | 39 |
| 11 | 56 | REALIZE NISSAN MECHANIC CHALLENGE GT-R | JP de Oliveira Teppei Natori |
78 | 2:25'19.299 | YH | 100 |
| 12 | 31 | apr LC500h GT | Koki Saga Kazuto Kotaka |
78 | 2:25'44.039 | BS | 42 |
| 13 | 11 | GAINER TANAX GT-R | Ryuichiro Tomita Keishi Ishikawa |
77 | 2:24'32.547 | DL | 78 |
| 14 | 7 | Studie BMW M4 | Seiji Ara Bruno Spengler |
77 | 2:25'03.688 | MI | 100 |
| 15 | 88 | JLOC Lamborghini GT3 | Takashi Kogure Yuya Motojima |
77 | 2:25'04.703 | YH | 48 |
| 16 | 360 | RUNUP RIVAUX GT-R | Takayuki Aoki Takuya Otaki |
77 | 2:25'10.632 | YH | |
| 17 | 22 | R'Qs AMG GT3 | Hisashi Wada Masaki Jyonai |
77 | 2:25'16.559 | YH | |
| 18 | 9 | PACIFIC VSPO NAC AMG | Ryohei Sakaguchi Jiatong Liang |
77 | 2:25'25.177 | YH | |
| 19 | 27 | Yogibo NSX GT3 | Yugo Iwasawa Reimei Ito |
77 | 2:25'25.534 | YH | 30 |
| 20 | 87 | Bamboo Airways Lamborghini GT3 | Kosuke Matsuura Natsu Sakaguchi |
77 | 2:25'30.486 | YH | 57 |
| 21 | 48 | Shokumou K's Frontier GT-R | Taiyo Ida Yuki Tanaka |
76 | 2:24'48.506 | YH | |
| 22 | 60 | Syntium LMcorsa GR Supra GT | Hiroki Yoshimoto Shunsuke Kohno |
76 | 2:25'04.314 | DL | 24 |
| 23 | 5 | MACHSYAKEN AIR BUSTER MC86 | Yusuke Tomibayashi Takamitsu Matsui |
71 | 2:17'12.210 | YH | |
| 24 | 30 | apr GR86 GT | Hiroaki Nagai Manabu Orido |
54 | 2:25'23.203 | YH | 6 |
| 25 | 2 | muta Racing GR86 GT | Yuui Tsutsumi Hibiki Taira |
10 | 14'56.215 | BS | 100 |
