Leclerc delivered Ferrari's first win on home soil since 2010 and secured back-to-back victories after fighting off Hamilton and his Mercedes team-mate Valtteri Bottas.
Hamilton was forced to take the escape route at the Roggia Chicane after being squeezed out by Leclerc as he mounted his strongest attack. The Ferrari man was issued the black and white warning flag as a result, but no time penalty followed.
Despite the warning, Leclerc said he was happy to push the boundaries in the search of victory.
"I knew it was on the limit, but at the end I wanted to give absolutely everything to have this win," Leclerc said.
"It was not in the back of my mind. I tried to be at the limit of what's acceptable, and that's what I have done, so very happy to take the win home."
One of Leclerc's near-misses earlier in the year came in Austria, where he led the vast majority of the race from pole, but succumbed to a late attack from Max Verstappen and finished second.
Verstappen kept that victory after a boisterous overtaking move was relayed to the stewards and Leclerc says the incident helped teach him how hard he could defend his place, which came to the fore in Monza.
He said: "Obviously I think since Austria it's clear that we can go a bit further in the way that we defend and overtake and yeah, just the aggressivity of us drivers.
"I believe that Austria helped me to change this approach and today it's also thanks to this that I've managed to win. It was obviously very on-the-limit but… yeah, I'm happy to race like this."
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