Norwich condemned relegation-threatened Leicester to a fourth successive home Sky Bet Championship defeat to end Gary Rowett's unbeaten start as manager.
Second-half substitute Anis Ben Slimane drilled the Canaries ahead just six minutes after coming off the bench at the King Power Stadium before Ali Ahmed's close-range finish sealed a seventh win in nine league games.
The result extended Leicester's winless league run to nine matches and kept them third bottom but further strengthened Norwich's bid for Championship survival as Philippe Clement's in-form side climbed 11 points clear of the drop zone.
Rowett had seen his side claim creditable away draws in his first two games since taking charge and they started brightly enough here, with Ricardo Pereira almost sending Bobby De Cordova-Reid clear, only for his through-ball to hit the midfielder's heel.
Harry Winks' swerving shot from the edge of the box then almost caught out Norwich goalkeeper Vladan Kovacevic after a good run from the lively Abdul Fatawu.
But Norwich began to take a grip on the first half, probing away down the left of the Foxes' shaky back four through Paris Maghoma and Ben Chrisene.
The travelling supporters celebrated prematurely as an unmarked Mathias Kvistgaarden met Maghoma's inswinging corner at the near post and headed into the side-netting.
Moments later Maghoma was given a free pass through Leicester's midfield all the way to the edge of the area and his goalbound low shot forced keeper Jakub Stolarczyk into a super fingertip save to turn the ball around a post.
Maghoma's corner almost dropped kindly for Ruari McConville in the six-yard box, only to bounce off the defender to a grateful Stolarczyk, a late replacement for Asmir Begovic who pulled up in the warm-up.
With former head coach Enzo Maresca watching from the stands, Leicester's final ball lacked quality and composure, summed up when Winks overhit a diagonal pass, aimed for Luke Thomas, straight out of play.
Divine Mukasa then flicked on a Thomas long throw across the six-yard box but found no Foxes takers as the half ended goalless.
The Canaries continued to threaten after the break, again finding openings down the left.
Maghoma bulldozed into the Leicester box and blasted a close-range shot at Stolarczyk's chest before moments later Ben Nelson came to the rescue to block Kvistgaarden's goalbound effort.
Kovacevic almost gifted the Foxes the lead when he miscontrolled a backpass straight to Patson Daka but recovered in time to leap on the loose ball.
Slimane came on for the dangerous Maghoma just after the hour and within minutes forced a brilliant save from Stolarczyk after Chrisene's cross had deflected into his path.
But there was nothing the Leicester keeper could do to stop his next effort as Slimane combined with Sam Field on the edge of the area and drilled a fine shot into the bottom left-hand corner after 68 minutes.
The goal extended Leicester's run without a clean sheet to 29 games and worse was to follow nine minutes later.
Kellen Fisher was allowed time and space from a set-piece by a dozing defence to advance and cross, with Stolarczyk deflecting Errol Mundle-Smith's shot across goal to the back post where an unmarked Ahmed poked home.
Leicester's Gary Rowett:
"Today, it just felt flat from the start, if I'm being honest, it was really disappointing.
"There was never really a period where I felt we were working hard enough on and off the ball to create moments and create pressure on Norwich."
"You see a lot of people here that are desperate to get out of the situation we're in, but we are where we are.
"As a group, as a team, as a club we've got a fight to get out of it. We've got good players, but there's no point having good players if we don't do the basics of the game. This is the Championship, this is a different type of league.
"There has to be a physical element in the games in order to win them. Today, we lacked a little bit of physicality, I thought, and athleticism."
Norwich's Philippe Clement:
"This is a hard place to come, a squad with a lot of quality, a lot of experience also.
"So for controlling the game almost fully, I think, today was a really, really big performance for my squad.
"They played a really good game tactically, technically, physically and also mentally.
"To do it in the right way and to make the right decisions in the right moments, to find the right spaces, to keep a clean sheet. So a lot of positives today again."
