Formula One world champion Lewis Hamilton equalled Michael Schumacher's record of five Italian Grand Prix wins and left Ferrari feeling the pain in their own backyard.
The Briton and Sebastian Vettel, his closest title rival now 30 points behind, collided at the fourth corner of the opening lap with the German Ferrari driver sent spinning down to 18th place before recovering to fourth.
Hamilton then twice overtook Kimi Raikkonen, who had started on pole, to dampen the spirits of Ferrari fans who had turned out in droves in the hope of celebrating a first home win in eight years.
New Zealander Brendon Hartley retired just after the start when he found his Toro Rosso sandwiched between Stoffel Vandoorne's McLaren and Sauber's Marcus Ericsson.
The contact broke the New Zealander's front-right suspension, forcing him out immediately.
The thrilling victory was a fifth in a row for Mercedes at Monza, the high-speed spiritual home of the sport's most glamorous and successful team, and one of Hamilton's most satisfying.
"Today was so difficult. Whilst the negativity is never great, that's what powered me along. I actually accept it," Hamilton told the crowd, who flooded the main straight with their flares and flags and booed him massively as he stepped onto the podium.
"I love being here in Italy...the track is incredible, and it's a such an honour to win here in front of such a great crowd."
While Vettel looked to be to blame for his own misfortune, he pointed the finger -- which he had hoped to raise in triumph -- at Hamilton.
"Lewis saw a little bit around the outside but he didn't leave me any space," the German told Sky F1 television. "I had no other chance (but) to run into him and make contact."
Others disagreed: "Sebastian Vettel cracked under pressure, it has to be said," commented 1996 world champion Damon Hill, with agreement from Hamilton's former team mate and 2016 champion Nico Rosberg.
"I think it was 100 percent Sebastian's fault. Lewis left him enough room," said the German.
Hamilton's sixth win of the season lifted him to 256 points, to his German rival's 226, with seven races left in what remains a fierce battle between the four times world champions.
Mercedes have 415 points to Ferrari's 390 in the constructors' standings.
Raikkonen had looked to be in with a chance of his first win in 108 races but the Finn, who seized back the lead after Hamilton passed him on lap four, was unable to hold off the Briton in the closing stages.
Hamilton, who had pitted later, passed the Finn again eight laps from the end and never looked back.
"I think it (the car) was quick enough but unfortunately our rear tyres went," said Raikkonen, who was hardly in the mood to celebrate his 100th podium in Formula One.
"It was a losing battle from that point. We did our maximum," said the 2007 world champion. "For sure we tried but the rear tyres gave up before the race ended."
The winner was also helped considerably by team mate Valtteri Bottas who led after Hamilton pitted and managed to hold up Raikkonen long enough for the other Mercedes to close the gap.
"I was really trying to do everything I can to get to the podium. First my mission was to hold off Kimi, and then I was challenging with Max," said Bottas.
Vettel, who made two stops including a first one to replace a damaged front wing, and Bottas both moved up a place at the finish after Red Bull's Max Verstappen was handed a five second penalty for pushing the Finn off track on lap 44.
Verstappen was fifth with Romain Grosjean sixth for Haas and Esteban Ocon seventh for Force India ahead of team mate Sergio Perez.
Renault's Carlos Sainz was ninth and Canadian Lance Stroll took a point for struggling Williams in 10th.