David Beckham has admitted he "lost control" during the dressing room spat with former manager Sir Alex Ferguson last February.
Speaking for the first time about the row which left him with a cut above his left eye, Beckham said his team-mates had to physically restrain him after he was hit by the boot kicked across the room by a furious Ferguson.
In an extract from his forthcoming autobiography, published in Monday's Sun newspaper, Beckham also claimed his Old Trafford fate was sealed after Ferguson blamed him for United's Champions League exit against Real Madrid last season.
"There was a boot on the floor. He swung his leg and kicked it," said Beckham.
"At me? At the wall? It could have been anywhere, he was that angry now.
"I felt a sting just over my left eye, where the boot had hit me.
"I put one hand up to it and found myself wiping blood away off my eyebrow.
"I went for the gaffer. I don't know if I've ever lost control like that in my life before.
"A couple of the lads stood up. I was grabbed by Giggsy first, then by Gary (Neville) and Ruud van Nistelrooy.
"Suddenly, it was like some mad scene out of a gangster movie."
The row erupted after Ferguson blamed Beckham for the second goal in Manchester United's 2-0 FA Cup defeat to Arsenal in February.
Beckham said he felt Ferguson was unfair, and he felt he was being "bullied" by the manager.
"I swore at him. Something no player, certainly no United player should ever do to the manager," added the England captain.
Beckham said his deteriorating relationship with the manager was affecting him off the field, and prompted him to quit the club.
And Beckham believes he was on his way out after United went out of the Champions League against Real last season.
He noticed Ferguson's anger at a wasted late free-kick, despite Beckham scoring twice after coming on as a substitute as United staged a comeback.
"He reacted as if I had just lost the game. As if, in that moment, I'd got us knocked out of the Champions League.
"His face told me everything I needed to know. His rage. His frustration. I was sure I was finished."