A BOOZY Royal Marines captain was knocked out cold in an amazing brawl in an officersâ mess, it was revealed yesterday. Trouble flared when the tough commando tried to gatecrash an invitation-only cocktail party. Officers of the 1st Battalion Royal Regiment of Fusiliers were celebrating after six weeks of war games exercises at a British Army training base in Canada. The plastered Marine â a helicopter pilot on temporary attachment to the infantry unit â turned up at 2am in search of more drink. A furious row broke out between him and five Fusilier officers when he was told he could not go in. Then the Marine swung a punch and a captain serving with the RRF knocked him unconscious with one blow. He was carried away by his NCOs and later made a formal complaint. But at an ID parade next day the groggy Marine wrongly picked out several officers who were NOT AT the party. A senior Army source said: âThis is not the sort of behaviour normally seen in an officersâ mess. It was appalling. âBut the captain who struck the blow was obviously provoked and had little option but to retaliate. âHe decked the Marine with a single punch â which must have taken some doing. âThe incident will go down in the regimentâs battle honours as RRF 1, Royal Marines 0.â Another source said: âThe Marine was out of his skull on booze when he tried to gatecrash the party. âThe ID parade the following day was a total farce â he obviously couldnât remember much about the night before.â The Royal Regiment of Fusiliers battle group had spent six weeks honing their fighting skills in rugged terrain near Calgary, Alberta. Army top brass ordered an immediate investigation into the incident, which is deeply embarrassing for the RRF. This year four RRF men were jailed over pictures of Iraqi prisoners being abused. And 21 of its soldiers were arrested after a brawl at a stag night in Germany. A Ministry of Defence spokesman said last night: âThere is an investigation into an allegation made of an incident in the officersâ 99.99% need not apply!