Yamamoto was the only driver to break the 1m22s barrier during four hours of on-track running on Friday, setting a time of 1m21.897s to claim the top spot by 0.112s.
When the pitlane opened at 10am the track still had visible damp patches in places, but it wasn’t long before the circuit was completely dry. However, most of the day’s quickest times were sset during the final 10 minutes of the afternoon session, when drivers equipped the OTS aid on their cars.
Kakunoshin Ota was the first driver to better Liam Lawson’s previous benchmark with a 1m22.442s, before Yamamoto moved the goalposts with a time that was over half a second up on the Dandelion driver.
His lap wasn’t to be bested as the session came to a close, with Ota’s team-mate Makino ending up as Yamamoto’s closest rival in second position with a time of 1m22.009s.
Ren Sato made it two Nakajima Racing cars inside the top three with a 1m22.193s flier, while TGM driver Toshiki Oyu - who had to retire from the previous race at Sugo with floor damage after starting from pole - made it an all-Honda top-four.
Just days after landing a plum seat at TOM’S in place of the benched Giuliano Alesi, Ukyo Sasahara finished a strong fifth and even managed to outpace his team-mate and championship leader Ritomo Miyata by exactly half a tenth.
Kazuya Oshima was seventh-fastest for Rookie Racing on the back of a promising result at Sugo last weekend, while Sho Tsuboi was eighth for Inging ahead of the lead Kondo car of Kenta Yamashita.
Ota’s time of 1m22.442s was only good enough for 10th at the end, as nearly the entire 22-car field ended up within one second.
The only driver to not make the one-second cut was Impul’s Yuhi Sekiguchi, who caused the only red flag of the day when his car came to a stop by the track in the morning session.
He finished just ahead of Mugen’s Tomoki Nojiri, who ended a difficult day in 21st place with a time of 1m22.984s.
Nojiri's team-mate and Red Bull junior Lawson ended up 12th-fastest, despite having set the quickest time in the morning session when no OTS was available to the drivers.
Afternoon session times:
| Position | Driver | Team | Time |
|---|---|---|---|
| 1 | Naoki Yamamoto | TCS NAKAJIMA RACING | 1'21''897 |
| 2 | Tadasuke Makino | DOCOMO TEAM DANDELION RACING | 1'22''009 |
| 3 | Ren Sato | TCS NAKAJIMA RACING | 1'22''193 |
| 4 | Toshiki Oyu | TGM Grand Prix | 1'22''229 |
| 5 | Ukyo Sasahara | VANTELIN TEAM TOM'S | 1'22''244 |
| 6 | Ritomo Miyata | VANTELIN TEAM TOM'S | 1'22''294 |
| 7 | Kazuya Oshima | docomo business ROOKIE | 1'22''306 |
| 8 | Sho Tsuboi | P.MU/CERUMO・INGING | 1'22''362 |
| 9 | Kenta Yamashita | KONDO RACING | 1'22''417 |
| 10 | Kakunoshin Ota | DOCOMO TEAM DANDELION RACING | 1'22''442 |
| 11 | Nirei Fukuzumi | ThreeBond Racing | 1'22''472 |
| 12 | Liam Lawson | TEAM MUGEN | 1'22''473 |
| 13 | Cem Bolukbasi | TGM Grand Prix | 1'22''530 |
| 14 | Yuji Kunimoto | Kids com Team KCMG | 1'22''557 |
| 15 | Kamui Kobayashi | Kids com Team KCMG | 1'22''569 |
| 16 | Ryo Hirakawa | ITOCHU ENEX TEAM IMPUL | 1'22''583 |
| 17 | Nobuharu Matsushita | B-Max Racing Team | 1'22''595 |
| 18 | Kazuto Kotaka | KONDO RACING | 1'22''667 |
| 19 | Hiroki Otsu | B-Max Racing Team | 1'22''774 |
| 20 | Sena Sakaguchi | P.MU/CERUMO・INGING | 1'22''777 |
| 21 | Tomoki Nojiri | TEAM MUGEN | 1'22''894 |
| 22 | Yuhi Sekiguchi | ITOCHU ENEX TEAM IMPUL |
1'23''264 |
Morning session times:
| Position | Driver | Team | Time |
|---|---|---|---|
| 1 | Liam Lawson | TEAM MUGEN | 1'22''919 |
| 2 | Sho Tsuboi | P.MU/CERUMO・INGING | 1'22''946 |
| 3 | Ren Sato | TCS NAKAJIMA RACING | 1'23''094 |
| 4 | Toshiki Oyu | TGM Grand Prix | 1'23''142 |
| 5 | Tomoki Nojiri | TEAM MUGEN | 1'23''181 |
| 6 | Tadasuke Makino | DOCOMO TEAM DANDELION RACING | 1'23''233 |
| 7 | Kazuya Oshima | docomo business ROOKIE | 1'23''270 |
| 8 | Ryo Hirakawa | ITOCHU ENEX TEAM IMPUL | 1'23''329 |
| 9 | Kamui Kobayashi | Kids com Team KCMG | 1'23''378 |
| 10 | Kenta Yamashita | KONDO RACING | 1'23''490 |
| 11 | Naoki Yamamoto | TCS NAKAJIMA RACING | 1'23''618 |
| 12 | Ritomo Miyata | VANTELIN TEAM TOM'S | 1'23''745 |
| 13 | Nirei Fukuzumi | ThreeBond Racing | 1'23''854 |
| 14 | Kakunoshin Ota | DOCOMO TEAM DANDELION RACING | 1'23''924 |
| 15 | Nobuharu Matsushita | B-Max Racing Team | 1'24''017 |
| 16 | Kazuto Kotaka | KONDO RACING | 1'24''033 |
| 17 | Ukyo Sasahara | VANTELIN TEAM TOM'S | 1'24''146 |
| 18 | Yuji Kunimoto | Kids com Team KCMG | 1'24''178 |
| 19 | Sena Sakaguchi | P.MU/CERUMO・INGING | 1'24''237 |
| 20 | Yuhi Sekiguchi | ITOCHU ENEX TEAM IMPUL | 1'24''353 |
| 21 | Raoul Hyman | B-Max Racing Team | 1'24''376 |
| 22 | Cem Bolukbasi | TGM Grand Prix | 1'24''572 |
