Written byRajdeep Saha
The youngster held off pressure from both Mercedes to clinch a nail-biting finish.
Meanwhile, it was a race to forget for Sebastian Vettel.
Leclerc won his second successive Grand Prix after clinching the race in Belgium last weekend.
This was Ferrari's first race victory at their home race since Fernando Alonso triumphed in 2010.
Ferrari won their 19th race at Monza (the highest ever).
Leclerc is now fourth in the standings this season (182 points).
He surpassed his Vettel (169) and is three short of Max Verstappen.
This was Ferrari's second race win in 2019.
Ferrari went past the 350-point mark this year after the Italian GP.
Meanwhile, Mercedes surpassed the 500-point mark (505).
Lewis Hamilton drew level with Michael Schumacher for the most podium finishes at Monza (8).
Hamilton also set the fastest lap during the race (1:21.779).
This was his third of the season.
Leclerc highlighted the importance of his win at Monza.
"I think if you have to win one Grand Prix with Ferrari it's the Italian Grand Prix. It's been a crazy week here. I come here with my first win [last week at Spa] and to win my second one here straight away with all the fans is just unbelievable," said Leclerc to Sky Sports.
Renault's Daniel Ricciardo and Nico Hulkenberg finished fourth and fifth respectively to collect 22 points between them.
Max Verstappen finished eighth to get four points. His Red Bull team member Alexander Albon finished sixth.
Sergio Perez (7th), Antonio Giovinazzi (9th) and Lando Norris (10th) were among the points as well.
Vettel, who once again committed a mistake, took a disappointing 13th place.
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