Lewis Hamilton said it felt unreal to become Formula One champion for a fourth time following a dramatic Mexican Grand Prix in which he collided with rival Sebastian Vettel on the opening lap.

Hamilton finished fourth after he allowed his Mercedes team-mate Valtteri Bottas past him on the last corner.

Although he did get a bit frustrated with Esteban Gutierrez at one point in the race.

Lewis Hamilton was involved in a series of heated radio exchanges with his Mercedes team during Sunday's European Grand Prix.

Lewis Hamilton secured victory in the Italian Grand Prix on Sunday as Mercedes team-mate Nico Rosberg showed another sign of cracking under the strain of this year’s Formula One world title fight.