Lewis Hamilton said he felt fortunate to be alive after a collision with Formula One title rival Max Verstappen at the Italian Grand Prix on Sunday.

Stewards handed Red Bull's championship leader Verstappen a three-place grid penalty for the next round in Russia after his car landed on top of Hamilton's Mercedes, with the rear tire hitting the champion's head.

The halo protection device, a titanium ring around the cockpit, took most of the impact in a crash that left both drivers out of the race at Monza.

"I feel very, very fortunate today, thank God for the halo. That did ultimately save me, you know, and saved my neck," seven-time world champion Hamilton told reporters.

"I don't think I've ever been hit on the head by a car before, and it's quite a shock for me."

"I'm so, so grateful that I'm still here. I feel incredibly blessed. I feel like someone was watching over me today."

Mercedes team boss Toto Wolff called a "tactical foul" but Red Bull counterpart Christian Horner said he was disappointed by the Austrian's comment.

"I think it's a racing incident and thankfully nobody was injured today," he said after a race that ended in a McLaren one-two with Australian Daniel Ricciardo the winner and Lando Norris the second. Valterri Bottas of Mercedes claimed the third prize. 

Stewards disagreed and said Hamilton's positioning was reasonable.

Moreover, Chinese racer Zhou Guanyu of UNI-Virtuosi Racing clinched the second place as Prema's Australian racer Oscar Piastri claimed the first prize during the F2 feature race at Monza Circuit.

British racer Dan Ticktum of Team Carlin took the third place.

(With input from Reuters)