Lawson finished fourth in Sunday's third round of the season as the top Honda-powered driver behind Toyota trio Ritomo Miyata, Sho Tsuboi and Ryo Hirakawa, continuing his strong start to his rookie campaign.
The New Zealander had made his way up from eighth on the grid to third before he made his mandatory pitstop when the window opened on lap 10 of 31, undercutting poleman and long-time leader Toshiki Oyu in the process.
However, Lawson was unable to get by Tsuboi when the latter made his stop on lap 11, and a subsequent safety car period caused by Nojiri making contact with Oyu allowed Miyata and Hirakawa, who hadn't stopped yet, to take the restart right behind Lawson.
Once the race resumed, Lawson quickly fell prey to Miyata - who would go on to pass Tsuboi for the win - and was passed by Hirakawa at Turn 1 at the start of the penultimate lap.
"I think we made the right strategy decision at the time," Lawson told Motorsport.com. "It was logical to pit early and try to undercut and we almost got the lead from it.
"The team did a great job, the car felt really good, especially later in the stint we had an advantage when the tyres were hot. It was just a badly-timed safety car that meant two other guys [Miyata and Hirakawa] came up behind me on brand new tyres and blitzed past.
"I needed the race to be longer to have that late-stint tyre advantage and for the race to come back to me again."
Asked whether knowing Nojiri was out of the race meant he took a more cautious approach after the final safety car restart, Lawson replied: "Definitely.
"When Ryo was behind me, he was quite aggressive into Turn 1. To be honest, I wasn’t expecting him to go around the outside. When I saw he was committing, instead of trying to hang on and risk a crash, I just conceded the place.
"Maybe I should have defended better, but for the sake of one position… fourth is still a good result considering the challenges thrown at us."
Lawson admitted however that just falling short of clearing Tsuboi while the latter was struggling to get his tyres up to temperature following his stop was something of a turning point in his race.
"In sector one at Suzuka it’s just single file, so you can’t do anything," said Lawson. "I had the grip and the speed advantage, but there was nowhere for me to go. By the time we arrived at the overtaking spots, his tyres were up to temperature.
"That was a crucial part of the race, because if we had been able to pass Tsuboi there, we would have been leading and potentially in clear air we could have had better pace.
"But considering those guys coming on new tyres, I think P4 was as good as we could do."
Lawson has halved the points deficit he had faced to Nojiri coming into the Suzuka race, with only seven points now splitting the two Mugen drivers in the standings.
