Sao Paulo - Esteban Ocon and Max Verstappen supplied a glimpse of Formula One's future with their impassioned battle on and off the track at the Brazilian Grand Prix.
The two young and highly-rated stars collided in an incident that cost Dutchman Verstappen of Red Bull his lead in the race - a setback that caused him to lose his temper afterwards in a violent confrontation with the Frenchman in the post-race drivers' weighing room.
The collision handed a 10th victory of the season to new five-time champion Lewis Hamilton - whose triumph confirmed Mercedes retained the constructors' title for a record-equalling fifth consecutive season -
Verstappen, who three times pushed Ocon forcibly and threatened to strike him, was ordered to carry out two days of community service under the direction of the sport's ruling body, the International Motoring Federation (FIA).
Their collision was a result of several years as rivals in junior formulae, in which both were identified as potential champions, as much as a fight for position in Sunday's race.
Ocon, who was attempting to un-lap himself, was given a 10-seconds stop-go penalty for causing the crash, but he was backed afterwards by his Force India team, Mercedes chief Toto Wolff and Hamilton, who had a grandstand view of the incident and said Verstappen was 60 per cent to blame.
The Mercedes driver pointed out immediately after the race that the impetuous Dutchman should have left more room because Ocon had "nothing to lose" and had every right to try and un-lap himself.
"I thought that it was fair game for him to try to un-lap himself," said Hamilton. "Of course, you don't want to cause an incident, but in those scenarios you give each other space.
"It's so simple to give each other space. You can never assume that the person's not up your inside because he's a backmarker and he's going to back off.
"You've got to acknowledge the fact that he may be there...(and think) I'm going to leave extra space because actually he's in a different race to me.
"That's my opinion about it. So, from my seat, it felt like it wasn't 100 percent one side. More like maybe it's 60-40..."
Formula One's official race director Charlie Whiting later explained why Ocon was punished.
He said the Frenchman was "absolutely" allowed to un-lap himself, but pointed out that it was the manner in which he attempted to do so that was wrong. He pointed out that Ocon, on fresher tyres, could have waited until Turn Four where Verstappen would have been more vulnerable to him.
"It's happened many times in the past," said Whiting. "But, of course, you expect it to be done safely and, more to the point, it should be done cleanly and absolutely without fighting.
"If he's got the pace then, normally, one would expect Red Bull to say 'Ocon has got the pace, let him through' or that sort of thing... It seemed he just went for it. It was just a bit unfortunate that he decided to fight for it, which was wholly unacceptable."
It was the first flashpoint clash between a back-marker and a race leader since the 2001 Brazilian race in which Verstappen's father Jos took out Juan Pablo Montoya and a reminder of the infamous 1993 Japanese Grand Prix after which an enraged Ayrton Senna knocked Eddie Irvine down with a punch.
However, Whiting added that it made no difference that Verstappen was the race leader.
"It makes it worse in a lot of people's eyes, but as far as the stewards are concerned, that doesn't matter."
The post-race fracas overshadowed a dramatic nail-biting finish to a thrilling contest, which confirmed another title double for Mercedes and a hot drivers' rivalry for the future with Ocon, expected to be in a Mercedes from 2020, enjoying many more fights with Red Bull's Verstappen.