Ferrari's Michael Schumacher was banished to the back of the Monaco Grand Prix starting grid on Saturday after stewards found him guilty of a driving infringement and stripped him of pole position.
The stewards said in a statement that the seven times Formula One champion had deliberately stopped his car on the track at the penultimate Rascasse corner in the closing seconds of qualifying, preventing rivals from setting a faster time.
Renault's Spanish world champion Fernando Alonso will now start on pole with Australian Mark Webber alongside in a Williams.
Schumacher's pole had triggered an immediate cheating controversy in the grand prix paddock, with rivals slamming the behaviour of the most successful Formula One driver the sport has ever seen in the season's glamour race.
Schumacher protested his innocence, claiming he had made a simple mistake, while stewards spent nearly eight hours reviewing the evidence before reaching a decision.
They said they found "no justifiable reason for the driver to have braked with such undue, excessive and unusual pressure at this part of the circuit and (we) are therefore left with no alternative but to conclude that the driver deliberately stopped his car on the circuit.
"The driver will start the race from the back of the grid," they added.
The German's excuses cut no ice with angry rivals.
"I hope it was deliberate, because if that was a mistake he should not even have an F1 superlicence," 1997 world champion Jacques Villeneuve told reporters.
"If you can make a mistake like that, you shouldn't drive a race car. There's no way you could make a mistake like that," added the Canadian, who won his title after a notorious clash with Schumacher.
Webber said: "I just feel you don't have to do this stuff. Why does it always have to happen? It's like Mike Tyson biting someone's ear off, isn't it?"
Alonso, who leads Schumacher in the title standings by 15 points, had said after qualifying that he would have been on pole had Schumacher not steered left at the slow Rascasse corner and then stalled.
That forced the champion to slow as marshals waved yellow danger flags, costing him vital tenths of a second.
Alonso, who has yet to step on the podium in Monaco, bit his tongue about what had happened but his team boss Flavio Briatore, who steered Schumacher to his first two titles at Benetton, had no such inhibitions.
"I think he is taking everyone for a ride," he told reporters. "Someone who was seven times a world champion wants us to believe that he didn't do it on purpose, it's fairyland.
"And given that we are not Snow White and the Seven Dwarves, I think that what he did was unsporting and against everything...It's really astonishing what he did. Incredible."
Pole position is particularly important in Monaco with the tight, twisting streets making overtaking almost impossible.
McLaren's Kimi Raikkonen, last year's winner, will move up to third place on the grid with Colombian team mate Juan Pablo Montoya alongside after Renault's Giancarlo Fisichella was demoted for impeding Red Bull's David Coulthard.
Schumacher, facing yet another controversy in a colourful career spanning 15 years, explained that he had simply locked up and run out of road.
"I tried to engage reverse but it didn't engage and I didn't really want to back up just by myself without knowing what was coming around the corner and finally it stalled," he said.
He suggested that those who doubted him should try to drive the car themselves.