Lewis Hamilton scored his 68th career victory at Monza and managed to escape unscarred from his first-lap contact with title rival Sebastian Vettel.
Hamilton overtook Vettel around the outside into the second chicane on the opening lap, and Vettel ran wide, hit the Mercedes and spun to the back.
Sebastian charged through to finish fourth behind Valtteri Bottas, as a time penalty dropped Max Verstappen from the podium to fifth.
Raikkonen maintained the lead despite pressure from Vettel and a lock-up into the first corner, before Hamilton drafted the Ferraris and attacked Vettel around the outside the Roggia Chicane.
Hamilton held his car level with the Ferrari, which drifted into the side of the Mercedes and spun.
Vettel dropped to the back and had to pit as he damaged his front wing in the contact as well, but was handed a silver lining thanks to a safety car.
Brendon Hartley pulled over on the right-hand side of the circuit seconds after the start, having been squeezed on the run to the first corner and suffered a front-right breakage on his Toro Rosso.
Racing resumed on lap four and Hamilton pressured Raikkonen but was not close enough to mount an attack.
That was the story of the opening stint as Hamilton gradually drifted outside of DRS range, but Raikkonen’s lead never rose above two seconds before he stopped on lap 20.
Mercedes was ready to receive Hamilton as well but instead the Briton did not pit and ran another eight laps, shipping five seconds to Raikkonen in that time.
However, Mercedes kept Bottas on track, with the Finn fighting to overhaul Verstappen, who had just pit, for third.
That meant Bottas was able to hold up Raikkonen and, within three laps of Hamilton pitting, he was within DRS range of Raikkonen and on fresher rubber.
Bottas led until lap 36 before pitting, releasing Raikkonen and Hamilton to duke it out for the win.
Hamilton was closer than ever as they crossed the line to start the 45th lap but only drew alongside the Ferrari as they approached the braking zone but nailed Raikkonen around the outside.
Raikkonen tried to fight back into the Roggia Chicane but Hamilton held the place and quickly broke clear as Raikkonen nursed a blister on his left-rear tyre.
That situation was so “critical”, as Ferrari put it, for Raikkonen that he fell almost 9 seconds behind Hamilton, whose victory extended his points lead in the championship to 30 as Vettel received a late gift by nicking fourth from Verstappen.
Bottas had used his fresh tyres to quickly wipe out Verstappen’s three-second lead and started to attack for the final podium place with ten laps to go.
He got a great run on Verstappen and pulled to the outside when Verstappen moved under braking for the first chicane, which bumped Bottas onto the grass and sent him onto the run-off.
Verstappen was hit with a five-second time penalty, then defended aggressively from Bottas when his rival recovered a four-second deficit, telling his team he did not care that he was costing himself time to Vettel.
That allowed Vettel, who stopped again in his fight back to fifth on-track, to sneak within five seconds of the Red Bull and salvage another two points.
Romain Grosjean was almost unseen on FOM but came under immense pressure from the Racing Point Force Indias in the best-of-the-rest fight.
Grosjean just held on to claim sixth for Haas, with Esteban Ocon besting a charging Sergio Perez – who started P14 – to P7.
Carlos Sainz finished ninth for Renault, while Lance Stroll claimed only the second points finish of the year for Williams as he completed the top ten.
Two drivers joined Hartley in retirement over the grand prix. Fernando Alonso stopped his McLaren with an unconfirmed problem on lap 10, while running in the points, while Daniel Ricciardo pulled a smoking Red Bull over exiting the second chicane just before mid-distance.
So congratulations to Lewis Hamilton and Mercedes in winning the Italian Grand Prix. This was an important result for the championship and taking victory at Monza was just magic.
Italian Grand Prix, race results:
1 Lewis Hamilton Mercedes 53 1h16m54.484s
2 Kimi Raikkonen Ferrari 53 8.705s
3 Valtteri Bottas Mercedes 53 14.066s
4 Sebastian Vettel Ferrari 53 16.151s
5 Max Verstappen Red Bull-Renault 53 18.208s
6 Romain Grosjean Haas-Ferrari 53 56.320s
7 Esteban Ocon Force India-Mercedes 53 57.761s
8 Sergio Perez Force India-Mercedes 53 58.678s
9 Carlos Sainz Renault 53 1m28.140s
10 Lance Stroll Williams-Mercedes 52 1 Lap
11 Sergey Sirotkin Williams-Mercedes 52 1 Lap
12 Charles Leclerc Sauber-Ferrari 52 1 Lap
13 Stoffel Vandoorne McLaren-Renault 52 1 Lap
14 Nico Hulkenberg Renault 52 1 Lap
15 Pierre Gasly Toro Rosso-Honda 52 1 Lap
16 Marcus Ericsson Sauber-Ferrari 52 1 Lap
17 Kevin Magnussen Haas-Ferrari 52 1 Lap
– Daniel Ricciardo Red Bull-Renault 23 Power Unit
– Fernando Alonso McLaren-Renault 9 Retirement
– Brendon Hartley Toro Rosso/Honda 0 Collision
1 Lewis Hamilton 256
2 Sebastian Vettel 226
3 Kimi Raikkonen 164
4 Valtteri Bottas 159
5 Max Verstappen 130
6 Daniel Ricciardo 118
7 Nico Hulkenberg 52
8 Kevin Magnussen 49
9 Sergio Perez 44
10 Fernando Alonso 44
11 Esteban Ocon 43
12 Romain Grosjean 35
13 Carlos Sainz 32
14 Pierre Gasly 28
15 Charles Leclerc 13
16 Stoffel Vandoorne 8
17 Marcus Ericsson 6
18 Lance Stroll 5
19 Brendon Hartley 2
20 Sergey Sirotkin 0
1 Mercedes 415
2 Ferrari 390
3 Red Bull-Renault 248
4 Haas-Ferrari 84
5 Renault 84
6 McLaren-Renault 52
7 Toro Rosso-Honda 30
8 Force India-Mercedes 28
9 Sauber-Ferrari 19
10 Williams-Mercedes 5