After the first set of saves, with Ricciardo in the lead, Hamilton came out of the pits in a third net just ahead of Verstappen as they descended to the first chicane on lap 26.
Verstappen tried to use his momentum around the outside of Turn 1 right and, as Hamilton moved to squeeze Verstappen towards the curb to protect his position, the pair came to blows at Turn 2 left.
Verstappen – who had been delayed by a slow 11-second pit stop – appeared to bounce off a curb at the top of the turn and was then thrown into the air – landing on top of Hamilton’s car as the pair went then immobilized in the gravel.
Verstappen quickly came to team radio and said, “This is what you get when you don’t leave space. “
The FIA said the incident will be investigated after the race, with the two drivers likely to be summoned to see the stewards.
Lewis Hamilton, Mercedes, gets out of his car after crashing with Max Verstappen, Red Bull Racing
Photo by: Zak Mauger / Motorsport Images
In the first lap of the race, Hamilton and Verstappen had already come close to fighting when the two battled wheel against wheel for second position at the second chicane.
Hamilton was forced through the relief zone, falling behind Norris, and complained about not leaving room.
Their end-of-race clash brought out the safety car, Ricciardo leading the race ahead of Charles Leclerc’s Ferrari and Norris in third.
Ricciardo then took the win, leading a McLaren 1-2 ahead of Norris, with Valtteri Bottas completing the podium in the second Mercedes which had started the race due to a powerplant change on Friday.
The Italian GP crash between Verstappen and Hamilton comes after the pair controversially collided in the first round of the British GP, the Dutchman firing in a 51g impact in the corner at high speed by Copse.
Hamilton was found to be primarily to blame and served a 10-second penalty, but still won the race with a late pass over Leclerc.