Huddersfield Town took a towelling as their away-day woes continued.
They were always likely to be up against it from the moment Murray Wallace was red carded for a professional foul just 17 minutes into the match.
But the manner of the defeat was a massive disappointment.
Three goals in six minutes at the start of the second half undid the good work which went before with Norwich, to the frustration of their fans, repelled before the break.
Chris Powell’s side rallied briefly, but two further goals arrived as the home side finished with a flourish to condemn Town to their heaviest defeat of the campaign, outdoing the 4-0 opening-day loss to Bournemouth.
A fourth successive away setback was a particular blow because Town, who last won at Carrow Road back in 1969 (it’s now 10 visits without a victory), initially looked capable of causing problems for Norwich, who had won just one of their previous eight home games.
Nahki Wells brought a smart save from England keeper John Ruddy and hit the bar from the rebound in the 11th minute as he worked hard to try and end a goal drought which has now lasted six matches.
Then came Wallace’s second sending off of the season as a lapse by fellow centre-back Mark Hudson left the Scot trying to dispossess Huddersfield-born striker Cameron Jerome, who went down under his challenge.
Hull referee Mark Brown had no hesitation, leaving Wallace, whose red against Charlton Athletic in August was rescinded, to serve a ban when Birmingham City come to the John Smith’s Stadium on Saturday.
With Joel Lynch unlikely to be back from his groin injury, Anthony Gerrard will be on stand-by for that one, but boss Powell elected against bringing him off the bench against Norwich.
Initially Conor Coady dropped back from midfield to central defence alongside skipper Hudson and Tommy Smith – with some success.
Both managers decided on changes over their half-time cuppas, Norwich boss Neil Adams bringing on flying England Under 21 ace Nathan Redmond for Gary O’Neil.
Powell, expecting the home winger to be introduced, sacrificed Wells for Paul Dixon, who went to left-back with Sean Scannell on the right and Jack Robinson moving infield to complete a three-man rearguard alongside Hudson and Smith, Coady returning to midfield next to Jacob Butterfield and Jonathan Hogg.
That left former Norwich favourite Grant Holt trying unsuccessfully to plough a lone furrow up front.
Redmond certainly made an impact as the Canaries went ahead just 45 seconds after the restart, Bradley Johnson profiting from Gary Hooper’s clever back-heel.
One became two as Redmond looped in a header from Swedish international left-back Martin Olsson’s cross, then three as Johnson nodded in the rebound after Robinson blocked Jonny Howson’s fierce shot.
Town looked at sixes and sevens, and Norwich looked capable of chalking up that many goals.
The yellow and green momentum was lost for a spell, and Smith’s deflected shot brought a fine tip-over from Ruddy.
But Norwich’s top scorer Jerome, having just been thwarted by Alex Smithies, made it 10 for the season with a 69th-minute header.
Then substitute Lewis Grabban drilled in his seventh goal since a close-season move from Bournemouth.
Norwich were celebrating their best win since hitting Scunthorpe United for six in April 2011.
For Town, it was a worst defeat since the 6-1 drubbing at Nottingham Forest in February 2013.
