Fernando Alonso hailed "probably the best lap of my career" at Suzuka, despite being restricted to 14th place on the grid.
Alonso, who last won at the circuit in 2006, made it through to Q2 at Honda's home event but posted the slowest time, finishing the session ahead of only the non-participating Max Verstappen.
"That was probably the best lap of my career around Suzuka," said Alonso. "I could have fitted 100 more sets of tyres to the car, and I probably still wouldn’t have bettered that Q2 lap-time.
"It’s frustrating to end up 14th, but that’s the situation at the moment. And it’s not as though anyone in the team is relaxing. No, we’re pushing hard, but there are no magic solutions.
"Tomorrow’s race will be tough – there are faster cars behind, such as Max’s, but we’ll do our best to try to get some points."
Jenson Button was only 16th after a communication error, and Verstappen's stoppage, restricted his prospects in Q1.
"The Q1 yellow flag in the middle sector meant I had to lift," he said, after qualifying outside of the top 10 at Suzuka for the first time in his career.
"Without that, I probably would have got through to Q2. However, I wasn’t told in which engine mode to put the car. Every time before we start a timed lap, we’re instructed over the radio to adopt a particular setting, but I didn’t get told, and I went to the wrong setting.
"The car didn’t feel too bad to drive – but we needed to get everything out of it today, and we didn’t. You can’t make a single mistake here – even going half-a-turn out on the front wing makes a big difference."