Sebastian Vettel admitted that he'd been on the back foot in practice at Suzuka but managed to find his form when it counted in Q3.
With Friday's track time proving badly compromised by the rain, Vettel could only manage eighth place in Saturday morning's dry practice session which left him two places behind his team mate Kimi Raikkonen.
Vettel continued to lag the Finn in the first two rounds of qualifying, but when it came to the all-important final pole shoot-out round Vettel was able to find something extra and put himself into fourth position while Raikkonen had to settle instead for sixth.
"It was a bit tricky, I didn't get into the rhythm straight away," he admitted.
"I was fairly happy with Q1, then Q2 I wasn't that happy with my first set on the medium tyres and then it turned out only attempting Q3 the car did come alive and I was a lot happier. The laptime was competitive.
"In any case there was only one more position to gain with Bottas in P3 but obviously we didn't have the last run. In any case I think it was fairly close between Williams, ourselves and probably the Red Bull as well."
Losing Friday's practice time to the rain certainly hadn't helped, he agreed.
"We got some information in FP3 but we were not yet where we wanted to be. In anyways we managed to recover and were a lot happier in qualie."
Vettel's final time in qualifying was still 0.661s off the pole-winning time set by Nico Rosberg, seemingly confirming that Mercedes were back on form again after the curious incident of the still-unexplained dip in performance at Singapore.
"It has been between three tenths and say eight tenths, nine tenths the whole season," said Vettel when asked about the gap between Ferrari and Mercedes in 2015.
"I think some tracks you feel a bit more comfortable and others you don't. Some tracks are coming maybe your way and others are not, but overall I think it's a representative gap.
"I don't know if they [Mercedes] had any margin - I think we had a bit - so you can argue about a couple of tenths but bottom line is that they are back to their competitiveness that unfortunately we've seen all year."
As well as the Mercedes drivers, Vettel will also have to overcome Valtteri Bottas if he's going to claim a podium position this weekend. With its Mercedes power plant, the Williams has proved consistently hard for anyone to pass it during the race leaving vettel with few options when it came to planning his attack for Sunday.
"The race is long," he insisted. "As you say they are not so easy to pass. If we are quicker then I think we have a chance. For sure, one of the first chances we will get is the start and then the way down to turn 1 is not that long but you never know.
"After that, with strategy you can try something, so I think it will be close tomorrow."
REPORT: Rosberg takes pole after huge Kvyat crash
AS IT HAPPENED: Japanese Grand Prix Qualifying
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