On a frustrating night for the lone strikers, it was a stunning strike from a left-back that separated the two teams in an even contest.
Open midfield but tight in the final thirds
Leicester went into the contest looking to halt a run of four games in all competitions without a victory in the absence of Jamie Vardy, the striker frustratingly short of joining the Premier League 100 club.
In contrast, Norwich were desperate just to net any number of Premier League goals - no strikes from open play since the first day of 2020. They recalled Emiliano Buendia, fourth in the top-flight charts for number of assists, amidst reports linking the Argentine away from Carrow Road.
Both sides sparred a chance apiece in the opening ten minutes, a header each testing the waters from corners. Hamza Choudhury nodded over on the stretch between the hosts' zonal marking before Ben Godfrey slipped into space to glance Ondrej Duda's cross straight at Kasper Schmeichel.
Whilst the midfield areas were open, the pathways to lone strikers Teemu Pukki and Kelechi Iheanacho were regularly closed, the pair contributing just five touches between them in the opening 18 minutes as Dennis Praet fired straight at Tim Krul from the edge of the area.
However, when the former goal-getter pulled into space, he was only thwarted by a brave block from Çaglar Söyüncü after Duda threaded Pukki through. Meanwhile, the Nigerian at the opposite end opted to drop deep to impact the play, blazing high and wide from distance.
Praet strikes the post as Leicester probe
It was Praet, with just one goal in 29 appearances this season, who looked the most likely to break the deadlock, guiding Ricardo Pereira's cross onto the post after Harvey Barnes had pulled Jamal Lewis and Godfrey out of position.
Maddison was beginning to pull the strings in midfield and his teasing cross was scrambled away by Krul as Iheanacho prepared to pounce, the closest the striker came to making contact with the ball in the Norwich penalty area in the opening 30 minutes.
Penned into their own half, Norwich were being forced to dig in, Ayoze Perez twisting and turning before his weak effort was jumped on by Krul.
Leicester were looking particularly threatening down the flanks and a fluffed clearance from Lewis was eventually worked by Perez across to Iheanacho who fired over from close range. Lewis looked void of confidence in the absence of Sam Byram, ruled out for the rest of the season with a hamstring injury.
Meanwhile, Pukki eased some of the pressure, bustling forward before a neat interchange between Buendia and Todd Cantwell resulted in the Norwich top scorer dragging an effort wide. But it wasn't long before Jonny Evans met another Maddison delivery, heading a corner straight at Krul.
No way through
As the half-time whistle blew, both sides were rueing a lack of creativity and potent goal threat.
The ball had regularly been worked wide but only Max Aarons averaged a pass success rate above 73% of the four full-backs, his opposing right-back the only one of the quartet to pull off a single accurate cross - resulting in Praet striking the post.
With 26 touches between them, Iheanacho had seen the ball as much in his own penalty area as he had at the other end of the pitch, the 23-year old and Pukki equating only three touches in the box and seven in the respective opposing final thirds.
The frustrations of the duo that resulted in them both regularly dropping deep were underpinned by Buendia averaging just a 61% pass success rate, a full 20% down on his season as a whole.
In the words of Delia Smith, 15 years ago, "Where are you? Let's be having you?"
Early goal ruled out
But just four minutes into the second half, the deadlock appeared to have been broken, ironically by Iheanacho curling home from outside the penalty area.
However, replays showed that the Nigerian had eased Godfrey out of the way, handling the ball in the process as he chased down Praet's pass over the top. VAR correctly overturned the goal. Lifeline for Norwich.
And the warning signs continued - Ben Chilwell whipping a cross to the back post but Perez could only head across goal and wide.
The link play between Buendia and Cantwell was few and far between but when they did combine, Norwich looked a threat. Duda picking up the conclusion of their interchange to force Schmeichel to tip over the crossbar.
Barnes then floated down the other end but cut a strike from range straight into the gloves of Krul.
Unlikely source strikes for Norwich
Buendia was starting to grow into the game and with his influence came real Norwich potency. The Argentine raced forward before playing the ball inside to Duda but the Slovak fired straight at Schmeichel when he had time to pick a spot.
However, the opener was to come from the most unlikely source. Aarons overhit a cross before the ball was picked up by Lewis on the angle of the penalty area. The left-back executed a perfect curling half-volley into the bottom corner to net his first Norwich league goal on his 82nd appearance.
Leicester immediately looked to recover and almost equalised through substitute Wilfried Ndidi, his header glancing wide with Godfrey's slight touch from Maddison's free-kick proving pivotal.
But the Foxes continued to look bereft of a focal point in the absence of Vardy, despite boasting the second highest number of Premier League goals in the final ten minutes.
Josip Drmic replaced the quiet Pukki and the Swiss striker forced Schmeichel to parry his curling effort away, moments before five minutes of injury time.
The lack of response at the other end was disappointing and it was Drmic again who went close to scoring, heading a bouncing ball into the arms of Schmeichel during the final seconds.
Full-time. A surprise result. Norwich within four points of safety.
Key takeaway
Fine margins
All too often on their return to the Premier League, Norwich have found themselves on the wrong end of costly mistakes or moments of quality to lose valuable points in the fight for survival.
Tonight it was their turn to benefit from the fine Premier League margins, Jamal Lewis proving an unlikely source with just his second Norwich goal after Kelechi Iheanacho had seen a strike ruled out by the debatable handball law.
Lewis had not enjoyed a fruitful night, just a 69% pass success rate, underpinning a tough debut season in the top-flight.
But Ricardo Pereira, arguably one of the best full-backs in the league this season, switched off at a vital moment. Drifting inside as the ball was spread to Max Aarons on the right, Ricardo found himself too central before strolling out towards Lewis, granting the left-back far too much time and space to pick his spot.