Leonardo Ulloa kept Leicester's title bid alive with a dramatic late winner to deny Norwich a priceless point.
The substitute fired in from close range with just two minutes left as the Foxes moved five points clear at the top of the Barclays Premier League with a 1-0 win.
Ulloa netted just his third goal of the season to get Claudio Ranieri's side out of jail as they struggled to break down a stubborn Norwich side who deserved a point.
Cameron Jerome missed the Canaries' best chance when he headed wide in the first half while John Ruddy saved from Marc Albrighton and Jamie Vardy.
Leicester were subdued for most of the game - thanks largely to Norwich boss Alex Neil's fine tactical tweak as the Canaries played with five at the back.
It shackled 19-goal Vardy, who struggled to make an impact, but Ulloa bailed them out late on.
Boss Ranieri has insisted their next five games - starting against the Canaries - were key to their title chances and they squeezed past their first assignment.
Norwich came to frustrate early and Kasper Schmeichel smothered just ahead of Jerome as the visitor's counter-attacking game plan became evident.
But it was Leicester who carved out the first decent chance when Russell Martin almost turned Vardy's cross into his own net.
In between, Robert Huth and Ryan Bennett looped headers over but the Canaries were content to play at their own pace.
They frustrated the league leaders, leaving little space for Vardy to exploit, although the danger of Riyad Mahrez and Albrighton was evident.
Albrighton came closest for the Foxes when his free kick dropped just wide but Norwich finished the half on top and Jerome should have out them ahead.
The striker - without a goal since December - rose highest to meet Robbie Brady's 39th-minute corner but glanced a six-yard effort wide.
Nathan Redmond was then denied by Schmeichel as the Canaries grew in confidence as they executed a fine first-half plan.
The visitors continued to see plenty of the ball after the break without creating another opening before Vardy drove at Ruddy after a neat free kick after 57 minutes.
The Foxes had been below par but the threat of Mahrez remained as the Algeria winger plotted to unlock Norwich.
Ruddy claimed Albrighton's effort after Martin's slip but the Canaries were nullifying Leicester's threat.
The outstanding Jonny Howson had hounded Mahrez and kept the Norwich midfield ticking as they looked to claim a precious result.
Ranieri responded with a double change, throwing on Jeff Schlupp and Andy King, before a final throw of the dice when he replaced debutant Daniel Amartey with Ulloa.
Leicester had kept Norwich's threat at bay as the Canaries dropped deeper, eager to protect a valuable point, but Redmond whistled an excellent 25-yard drive inches wide with seven minutes left.
But, with two minutes left, Ulloa popped up at the far post to fire in Albrighton's cross from point-blank range.
Patrick Bamford shot wide as Norwich tried to respond but Leicester clinched a vital victory.
TWEET OF THE MATCH
"Substitute Ulloa bags a late one for Leicester. Claudio we love you!" - @GaryLineker clearly believes this is Leicester's year.
Kasper Schmeichel: 6
Daniel Amartey: 6
Robert Huth: 6
Wes Morgan: 6
Christian Fuchs: 6
Riyad Mahrez: 7
Danny Drinkwater: 6
N'Golo Kante: 6
Marc Albrighton: 6
Jamie Vardy: 6
Shinji Okazaki: 6
Jeff Schlupp: 6
Andy King: 6
Leonardo Ulloa: 6
John Ruddy: 7
Russell Martin: 7
Timm Klose: 7
Ryan Bennett: 7
Ivo Pinto: 7
Alex Tettey: 7
Jonny Howson: 8
Nathan Redmond: 7
Robbie Brady: 7
Steven Naismith: 7
Cameron Jerome: 6
Matt Jarvis: 6
Patrick Bamford: 6
STAR MAN: Jonny Howson - The former Leeds midfielder was detailed to pick up Riyad Mahrez when the winger moved inside and he did a fine job of keeping the Algeria international silent. H owson kept Norwich playing and was at the heart of a robust defensive effort which should have yielded a point. They will need that kind of fighting spirit if they are going to stay in the Barclays Premier League this season.
MOMENT OF THE MATCH:
It looked like Leicester would have to settle for a point after a gritty performance by Norwich frustrated the hosts. There were few clear cut chances for either side until Leonardo Ulloa's goal two minutes from time. It sparked delirious scenes at the King Power Stadium to show how much the Foxes had got out of jail against the Canaries.
MOAN OF THE MATCH:
N'Golo Kante had rightfully earned plaudits for his outstanding season this year but in the week when France manager Didier Deschamps singled him out for praise the midfielder was disappointing. His distribution was poor and he lost possession, occasionally allowing Norwich to break and putting his team-mates under pressure. He was taken off in the second half but after a fine debut season the odd off-day can be forgiven.
VIEW FROM THE DUGOUT:
Claudio Ranieri will know his side need to perform better - and they have done this season - but the manner of their victory hinted they can grind out victory when needed. Norwich deserved a point and their performance was a marked improvement from some of their previous showings. It will devastate the Canaries being so close to a point but Alex Neil's side showed plenty of promise in their fight for survival.
Leicester v West Brom (March 1, Premier League)
Norwich v Chelsea (March 1, Premier League)