Michael Carrick felt his Middlesbrough side were not at their best despite hitting Norwich for five at the Riverside.
Boro climbed to third in the Championship after emphatically seeing off their promotion rivals 5-1 and closed the gap on second place Sheffield United to five points, though the Blades do have two games in hand.
Cameron Archer got a brace for the hosts with fellow Aston Villa loanee Aaron Ramsey also among the goals, along with Hayden Hackney and the Championship's top scorer Chuba Akpom, who bagged his 27th league goal of the season.