Lewis Hamilton branded Sebastian Vettel a "disgrace" after the German was deemed to have deliberately crashed into his title rival during a chaotic Azerbaijan Grand Prix.
The Formula One championship burst sensationally into life following four Safety Car periods, one red flag, and the spectacular demise of the sport's so-called friendly rivalry.
Red Bull driver Daniel Ricciardo won the race, while Hamilton's Mercedes team-mate Valtteri Bottas recovered from last to finish second as 18-year-old rookie Lance Stroll completed the most unlikely of podiums.
Vettel finished fourth, while Hamilton crossed the line just 0.2 seconds behind his rival.
Controversy erupted on lap 19 when Vettel rammed into the back of Hamilton as the Safety Car was deployed for a second time. The 29-year-old German, furiously gesticulating with both hands, then pulled alongside Hamilton before inexplicably driving into the side of his rival's car.
Niki Lauda, the non-executive chairman at Hamilton's Mercedes team and a three-time world champion, described Vettel's actions as "crazy".
For his part, Vettel denied any wrongdoing, accused Hamilton of brake-testing him, and claimed his 10-second stop-and-go penalty, and latterly three points on his driver's licence, were unduly harsh.
But it was not a view shared in the paddock, where Hamilton, now further adrift of Vettel in the title race, was the first to lay down the law.
"For him to pretty much get away with driving into another driver is a disgrace," Hamilton said. "I think he disgraced himself today. If he wants to prove he is a man we should do it out of the car, face to face.
"It is a misjudgement from him and some people don't like to own up to their own mistakes.
"The stewards looked at my data and the reason I didn't get a penalty is because I clearly did not brake-test him. It could not be clearer. It is as clear as blue skies.
"Ultimately what happened was disrespectful. There are kids watching us on TV.
"You think a multi-time world champion would behave better than that. I really hope that kids don't see that and think that is the right way. That is not how you drive."
Lauda was equally disparaging. Asked if the incident tainted Vettel's reputation, the Austrian said: "Sure. He freaked out in himself.
"When you hit somebody up the a*** it is your fault. No question. But to drive next to him and hit him on purpose, I have never seen anything like this.
"To do that I don't understand. Vettel is a decent guy, normally. This I don't understand. He is crazy."
Lauda added: "Lewis will hit him one day. Not with the car but with the fist. If I was Lewis, I would speak to Sebastian and ask him what is wrong.
"Sebastian said he didn't do anything wrong. This is his normal reaction. He is still somewhere else in his brain. After three days hopefully he realises."
Vettel, however, showed little sign of backing down. While he vowed to speak to Hamilton, an apology, it seemed, was not on the cards.
"We had a little contact, but I drove alongside him, mostly to raise my hand. I did not give him the finger. I just wanted to tell him, because I can't literally talk to him, that what he did was not right.
"I don't agree with the penalty I got. If you penalise me then you should penalise both of us because that was not the way to do it."
Hamilton's rivalry with Vettel had, until that point, been built on cordial relations. It evaporated in an instance. "He brake-tested me," yelled Vettel over the team radio. "What the f*** is going on?"
Vettel, who has won 45 grands prix, insisted that his reputation had not been affected.
"We are grown-ups, and we are expected to race, use our elbows, and that is what people want."
Hamilton, who now trails Vettel by 14 points in the championship, led the opening phase of a frenetic race and probably would have won, only for his headrest to come loose.
The Englishman tried to repair the flapping piece of bodywork by holding it down with his right hand while using his left to grasp the steering wheel as he reached speeds in excess of 220mph.
The stewards took a dim view, and ordered Mercedes to haul him in. A reluctant Hamilton stopped at the end of lap 31 for 9.3 seconds and emerged in ninth place.
As he headed out of the pit lane, Vettel was hit with his penalty, which he served two laps later. He arrived back on track ahead of Hamilton.
Vettel and Hamilton charged back through the pack, but the Briton was never quite close enough to exact his revenge. Later, Hamilton was informed that Vettel planned to phone him to cool the air.
"Firstly he doesn't have my number," he replied. "I am going to do my talking on the track. I want to get my head together, kill it, and win the next 12 races. That will say enough."
Ricciardo, meanwhile, who started 10th, was celebrating after winning his first race since last October's Malaysian Grand Prix. (© Daily Telegraph, London)