Leclerc claimed victory at Monza for the second time after winning in 2019, holding off McLaren pair Oscar Piastri and Norris in a thrilling race in which Verstappen finished nearly 38 seconds off the pace in sixth.
Huge roars engulfed the stands as Leclerc took the chequered flag for his second win over the season, after his own home Monaco GP, after holding out on a set of hard tyres he had changed during his one and only pit stop on the 16th lap.
"I thought that the first time would feel like this and the second time wouldn't feel as special," said Leclerc as he basked in the cheers of fans who made the track a joyous, noisy sea of red after the race.
"But my god the emotions in the last few laps; Monaco and Monza are the two races I want to win every year and I've managed to win them this year. It is so, so special."
All of Leclerc's major rivals, apart from teammate Carlos Sainz who ended up finishing fourth ahead of his Ferrari replacement Lewis Hamilton, pitted twice and McLaren were hoping that the Ferrari pair would do the same.
Instead, Leclerc managed to keep his tyres in good enough condition to stay ahead and in the end finish the race comfortably in front of Piastri, who had taken the race lead early on after an overtake manoeuvre on Norris which was as daring as it was tactically questionable.
"Not going to lie it hurts a lot. I did a lot of things right today," said Australian Piastri.
"Happy with the race, the pace I achieved but when you finish second it hurts."
Verstappen woes
Briton Norris - who clocked the fastest lap right at the end - will be disappointed by his finish after starting on pole but he managed to chop Verstappen's championship lead to 62 points with eight races remaining as his Dutch rival's barren run continued.
"We considered (pitting once) the whole race but it was impossible with our graining. Just disappointed. Ferrari did a better job, so hats off to them," said Norris.
Verstappen has now failed to win any of the last six GPs after claiming the honours in seven of the first 10, and his and Red Bull's dominance of F1 looks increasingly in question.
A fourth straight world title looked a near certainty when Verstappen won in Spain back in June, but since then he has only finished on the podium twice.
And his teammate Sergio Perez finishing in eighth meant that McLaren are now only eight points behind Red Bull in the constructor's standings and look favourites to win it for the first time since 1998.
Argentine rookie Franco Colapinto, who replaced axed Logan Sargeant for Williams following his disastrous showing at the Dutch Grand Prix last weekend, finish in 12th in his F1 debut.
