Norris qualified close to the front-row starting Red Bulls of Max Verstappen and Sergio Perez on Saturday.
But on Sunday it quickly became apparent Norris' real battle was with the cars behind, with Carlos Sainz being an immediate threat and Charles Leclerc fighting his way back into contention with a bold one-stop strategy.
Just seven months ago the McLarens comfortably claimed a double podium at Suzuka, but given Ferrari's vast race improvements, Norris admitted the Scuderia was out of reach this time around.
"It was as expected, to be honest with you," Norris said when quizzed by Autosport about sliding back to fifth.
"It was hard in the beginning when you're trying to push to keep up with a quicker car or push to stay ahead of the Ferraris, which were quicker.
"You hurt the tyres more and it's just kind of like a bit of a spiral, fighting a losing battle out there.
"So, not a bad day. We are where we kind of expected to be in the end, which is behind Ferrari. It's where we've been all year.
"Yesterday we just excelled, I put in some very strong laps, and made us look maybe a bit too good. And today it was a bit more back to reality."
Source: Autosport