Miyata ended up finishing fourth in a chaotic race that was red-flagged for the huge first-lap pile-up that was triggered by championship rival Liam Lawson spinning exiting Turn 2 while dicing for the lead with Tomoki Nojiri.
While Lawson was ultimately able to rejoin the field when the race was restart, he finished outside of the points in 13th, with Miyata now eight points clear of the Red Bull junior in the title race.
Both Miyata and his TOM'S team went into the Motegi weekend expecting to lose ground to Lawson at what has historically been a difficult circuit for the Toyota flagship squad.
And when Miyata failed to get off the line from eighth on the grid, dropping to the back of the pack, the 24-year-old admitted that he wasn't hopeful of mounting such a strong recovery drive.
"Because I didn’t have the pace to recover [from a bad qualifying position] last year, after going into anti-stall I wasn't confident I could catch up," said Miyata.
"But in the event the pace was better than I had expected. I was able to overtake other cars and create some highlights.
"There was no way I thought I would end up with the points lead. Rather, I thought Liam would end up 10 points ahead of me.
"And then, when I went into anti-stall, I was just thinking, ‘it's over.’ It was thanks to the team that I was able to recover."
After dropping as low as 17th, Miyata had made his way up to 12th when the mandatory pitstop window opened on lap 10, and was one of the last to make his tyre change by staying out until lap 29.
On fresh tyres, he was able to pass an early-stopping Sena Sakaguchi for fourth place on lap 31, and fell just shy of overhauling a struggling Toshiki Oyu for third, circulating up to two seconds faster in the latter stages.
Miyata now heads to the final double-header of the season at Suzuka, where he secured his first Super Formula win earlier in the year.
"Finishing fourth here was something I couldn’t expect, and it’s great to go into Suzuka as the points leader," said Miyata. "It’s the circuit where I took my first win, so I don’t think I’ll have the same worries as I had this time.
"Honda has been strong there for the past two or three years, but I want to approach the weekend with confidence."
Motorsport.tv is showing all Super Formula qualifying sessions and races live in 2023. Click here for further information and to sign up today.
