Charles Leclerc pulled off an extraordinary home win for Ferrari at the Italian Grand Prix, ahead of the McLarens of Oscar Piastri and Lando Norris.
Ferrari chose a one-stop strategy for Leclerc, improvising mid-race, to vault him in front of the McLarens - who chose the conventional two-stop approach.
That left Leclerc hanging on in the closing laps from the rapidly closing McLarens and he just managed to resist them, winning by 2.6 seconds to send the tifosi in the grandstands wild.
Red Bull's Max Verstappen could finish only sixth, and Norris cut his championship lead by eight points to 62 with eight races to go, thanks to Norris grabbing the fastest lap before the chequered flag.
McLaren are now just eight points behind Red Bull in the constructors' championship.
After locking out the front row of the grid, McLaren looked on course for a one-two for half the race, with Piastri leading Norris after the Australian passed the Briton around the outside of the second chicane on the first lap.
Piastri's fair but aggressive move ended with Norris slipping down to third in the first stint of the race as Leclerc was also able to slip by into second on the exit of the corner.
After trailing Piastri and Leclerc through the first stint, Norris made his pit stop first, in an attempt to undercut his way by Leclerc, who responded on the following lap.
Ferrari pitted on the next lap but McLaren's strategy worked, vaulting Norris ahead of Leclerc, who initially complained on the radio.
McLaren pitted Piastri to ensure he kept the lead, following their team rules of being fair to both drivers, and the race now seemed to be a fight for victory between the two McLarens.
But Norris began to struggle with tyre wear, slowly dropping back to five seconds behind Piastri and had to make a second pit stop on lap 32, with 21 to go, Piastri following him six laps later.
There will be questions as to whether McLaren, worried about heavier front tyre wear than Ferrari, should have stayed out in front and gambled on their tyres lasting.
Their decision to pit left Leclerc leading his team-mate Carlos Sainz by just over 10 seconds with Piastri chasing both down, and Ferrari decided to chance their arm.
They knew a one-stop option would be difficult, especially with such an early first stop, but both drivers pulled it off.
But, while Sainz dropped back to fourth behind the two McLarens, Leclerc's lead was enough to keep him in front, to take one of the most stunning and unlikely victories of the year.
The crowd cheered him across the line as he took his second Monza victory for Ferrari, after his first in 2019.
"An incredible feeling," Leclerc said. "I thought the first time would feel like this and the second time, if there was one, wouldn't feel as special.
"But my god, the emotions in the final laps - just like 2019. Incredible.
"Monaco and Monza are the two races I want to win every year.
"Obviously I want to win as many as possible, and the world championship as soon as possible, but these are the two most special and I have managed to win them this year. It is so, so special."
Piastri said losing out on the win "hurts", adding: "With the position we were in, with the tyres looking like they did, the one-stop seems like a very risky call but it was right. Very happy with my race, but when you finish second it hurts.
"In hindsight, yes [we should have gone for a one-stop]. Everyone's a legend after the flag. Today we got it wrong, me being a big part of that, we had everything to lose from the lead.
"Charles could try something different. He was going to finish third and he picked the right gamble.
"The hard was looking pretty grained but we didn't expect it to clean back up again, but it did."
Norris was disappointed with third but can still look back on a race in which he gained more points back on Verstappen, and he still has the same task as before - to score on average just under eight points more per race than the Dutchman to win the title.
Behind Sainz, Hamilton was fifth, well ahead of Verstappen, who had a dire race for Red Bull.
Unlike the rest of the top 10, both Red Bulls started on the hard tyres rather than the mediums, a questionable choice from the point of view of some rival strategists.
They fitted them again at his first pit stop on lap 22, only six after Piastri's first stop to come off the mediums.
That meant Verstappen would have to stop again, to fit the medium tyres, and worse than that he had a slow stop, taking him six seconds. His race was always looking tricky from there, especially as Red Bull have lost their pace advantage over their rivals in recent races.
The second Mercedes of George Russell won a battle with Verstappen’s team-mate Sergio Perez for seventh.
The Briton started third, but he dropped to seventh at the first corner after misjudging his braking behind Piastri, clipping the McLaren and damaging his front wing and taking to the run-off area.
Taking the final points - in ninth and 10th - were Williams' Alex Albon and Haas driver Kevin Magnussen, who is set to be banned for the Azerbaijan Grand Prix after causing a collision with Pierre Gasly, taking the Dane to 12 penalty points.