Red Bull's Verstappen held off Lando Norris and championship leader Oscar Piastri after setting the fastest lap in F1 history when taking top spot on the grid on Saturday.
The Dutchman has little chance of securing a fifth straight drivers' title as he still trails Piastri by 94 points with the Australian finishing third.
Piastri leads the drivers standings by 31 points from Norris who finished second, as the top five positions ended up staying as they were on the starting grid of a rapid race.
Sunday's win was just Verstappen's third of a season dominated by a McLaren car which has blown way the competition by winning all but four GPs.
But a second win in Italy this year, after triumphing in the last Emilia Romagna GP back in May, caps a historic weekend for the blunt 27-year-old.
Charles Leclerc couldn't take a podium spot for the massed ranks of Ferrari fans in the stands, the Monegasque finishing fourth.
Leclerc's teammate Lewis Hamilton gave it his best shot after a five-place grid penalty had him bumped back to 10th at the start, charging up to sixth thanks to some spectacular driving early in the race.
But the seven-time F1 champion couldn't push past his former Mercedes teammate George Russel and was left with another underwhelming result in his first Monza GP with Ferrari.