A bouncer killed a man on a stag night after he was thrown out of a lap-dancing club for ignoring a 'don't touch' rule, the Old Bailey heard.
Marcus Marriott (33) punched marketing executive George MacDonald, from Warwickshire, after he was thrown out of the West End club for pulling a lap dancer towards him.
Marriott, an amateur heavyweight boxer, smashed Mr MacDonald's jawbone and sent the 21-stone man crashing to the pavement, where he fractured his skull and died.
Mr MacDonald, aged 34, from Southam, was out with a group of friends on a joint stag night and birthday party when he died in the early hours of October 8, 2004. Dorian Lovell-Pank QC, prosecuting, said: "They all had dinner in Piccadilly. Some of them went on to a casino in Mayfair and four of them, including Mr MacDonald, ended up at Stringfellows.
"Mr MacDonald was a big man. He was six feet one inch tall and weighed 21 stone, and he had had quite a lot to drink by the time he and his friends arrived."
He went on: "At Stringfellows the dancers do stripteases, pole dances and lap dances and you can have your own private little show if you're prepared to pay for it.
"There's one important house rule which is you're not allowed to touch the girls at all and if you do you're likely to be asked to leave the club."
Mr Lovell-Pank said that Mr MacDonald began chatting to one of the dancers and she had danced for him.
He went on: "It seems he pulled her towards him or touched her in some way. This was seen by one of the doormen and, as a result, he was asked to leave the club."
Mr MacDonald was escorted out of the club by two bouncers.
They were joined by Marriott, a trained martial arts expert and amateur boxer who had fought competitively at cruiser and heavyweight levels under the name Marcus Lee.
Mr Lovell-Pank said: "Mr MacDonald was drunk but he was able to walk up the flight of stairs unaided.
"He was quite drunk but he was celebrating a birthday and had been on a stag night and if he wanted to get drunk that was his business.
"He was apparently making comments such as 'you think you're a big boy' to the defendant.
"In the next 30 seconds the defendant had punched Mr MacDonald so hard in the face that it shattered his upper jawbone and sent his 21-stone body crashing to the pavement where he fractured his skull."
Mr MacDonald died minutes later. Jurors were shown CCTV footage which captured the whole incident, which was also witnessed by a police officer in a patrolling van.
Marriott was arrested and taken to Charing Cross police station where he accepted he had punched married father-of-two Mr MacDonald, a self-employed computer expert.
But he claimed Mr MacDonald was threatening him and insisted he had only struck out in self-defence.
He told police that the death was his "worst nightmare", jurors were told.
Marriott, of St John's Road, Chingford, east London, denies manslaughter.
The trial continues.