Honda junior Yusuke Mitsui took the Japanese Formula 4 points lead at Sportsland SUGO.
The 44-car field was split into two groups for qualifying, and Group A headed out on a damp track with grooved tyres. Mitsui was fastest by 0.479 seconds over Toyota junior Yuki Sano, with Honda junior Tosei Moriyama the only other driver within a second of Mitsui.
But Mitsui started second for race one, as track conditions improved considerably for Group B who ran on slick tyres. In a far quicker and more competitive session, Honda junior Yuto Nomura took pole with a 1m26.113s lap that was 7.818s faster than Mitsui’s benchmark.
Bionic Jack Racing’s Jiei Okuzumi and Kazuhia Urabe were second and third fastest in Group B, 0.12s and 0.267s behind Nomura respectively, putting them third and fifth on the grid. Points leader Rikuto Kobayashi qualified 10th.
It remained dry for race one, and at the start Nomura and Mitsui broke away. The top five maintained positions, while Toyota junior Jin Nakamura passed Moriyama for sixth at turn one on lap two and Kobayashi got into eighth.
A spin into the gravel for Yoshiaki Nakamura then led to the safety car being required, with racing resuming on lap six.
Sano attacked Okuzumi for third through the first corners of the lap, with both easing each other off the track before Sano got ahead. That battle enabled the top two to break away again. Urabe also got edged off the asphalt and fell to seventh.
Okuzumi was relegated to fifth by Jin Nakamura on lap eight, and soon had Moriyama, Kobayashi and Urabe attacking him.
Nomura won, always keeping Mitsui out of attacking distance, and Sano resisted pressure from Nakamura for his second podium.
On lap 10 of 17, Moriyama passed Okuzumi around the outside at turn one, with Kobayashi and Urabe following through a few corners later. Rin Arakawa also got past Okuzumi before the lap’s end, who late in the race fell to 10th. Kobayashi’s sixth place dropped him to third in the standings behind Mitsui and Nomura.
The difference in track conditions during qualifying also impacted race two’s grid, since drivers’ second-best laptimes were used, and Urabe took pole by 7.548s over Mitsui with a 1m26.391s. He topped his own group by 0.194s over Okuzumi.
Urabe converted pole into victory, resisting pressure from Mitsui until he went wide at turn one on lap eight and dropped back. He was back on Urabe’s gearbox on lap 15 as they tried lapping Tadakazu Kojima, but the safety car then led the field to the finish after Reijiro Yamazaki spun off.
Sano took third from Okuzumi at the end of lap two, but then Moriyama passed both into turn one to make the podium.
Jin Nakamura took less than five laps to go from 14th to seventh, passed Sano and Arakawa in a double move for fifth and finished fourth while Okuzumi sank to 13th.
Ryoma Henzan was eighth despite stalling at the start, and an off for Kobayashi left him 22nd.
Race 1 (17 laps)
1 Yuto Nomura HFDP 27m06.594s
2 Yusuke Mitsui HFDP +0.619s
3 Yuki Sano TGR-DC RS +4.702s
4 Jin Nakamura TGR-DC RS +5.277s
5 Tosei Moriyama HFDP +8.316s
6 Rikuto Kobayashi TGR-DC RS +9.312s
7 Kazuhisa Urabe Bionic Jack Racing +12.261s
8 Rin Arakawa Zap Speed +16.762s
9 Itsuki Sato Helm Motorsports +17.284s
10 Jiei Okuzumi Bionic Jack Racing +18.285s
Pole: Nomura, 1m33.931s
Fastest lap: Nakamura, 1m24.438s
Race 2 (17 laps)
1 Urabe 26m11.166s
2 Mitsui +0.129s
3 Moriyama +0.307s
4 Nakamura +1.723s
5 Sano +2.016s
6 Yuta Fujiwara Akiland Racing +2.616s
7 Arakawa +4.343s
8 Ryoma Henzan Buzz Racing +5.075s
9 Kento Omiya PONOS Racing +6.178s
10 Ryota Horachi Akiland Racing +6.868s
P: Urabe, 1m26.391s
FL: Nomura, 1m24.827s
1 Mitsui 160 2 Nomura 139 3 Kobayashi 138 4 Nakamura 123 5 Moriyama 87 6 Sano 64 7 Arakawa 56 8 Urabe 47 9 Horachi 39 10 Shunji Okumoto 33