A boxing champ dealt his boss a knock-out blow during a row at a Brighton conference.
Mickey Cantwell, 45, kicked Alan Irwin on the bottom before landing a punch on the side of his head.
The force of the right hook left 54-year-old Irwin out for the count as he lay on the floor of the ambassador suite at the seafront Metropole Hotel.
At Lewes Crown Court Cantwell, British flyweight champion in 1996, admitted assault causing actual bodily harm and claimed he had struck out because he felt "bullied."
The court was told that trouble flared on September 9 last year during the TUC Congress in the city.
Ann Toynbee, prosecuting, said Cantwell was working at the time as chief executive of the Professional Boxing Association and also as a project worker for the Educational Sports Forum, set up to provide help for sportsmen and women at the end of their careers who want to re-train in a new profession.
He was asked to step in to give a presentation at a lunchtime fringe meeting after former world champion boxer Barry McGuigan pulled out at the last minute.
The two men were going through paperwork ahead of the meeting when Cantwell became angry because he had not been given enough notice to prepare for the presentation.
Ms Toynbee said: "Mr Cantwell threw a leaflet at Mr Irwin who indicated he did not need this sort of aggravation.
"Mr Irwin turned around only to be kicked on the backside by Mr Cantwell. As he turned around he was immediately punched to the side of the head.
"He fell to the floor and was knocked out for a few seconds." The court was told that Cantwell, who has no previous convictions, lost his job after the attack and is now unemployed.
Judge Anthony Scott-Gall said: "Things went wrong and something snapped. You kicked Mr Irwin in the bottom and you did something wholly out of character, which any professional boxer knows within their bones they should not do, you thumped him."
Cantwell was ordered to carry out 200 hours of unpaid work in the community and must pay £1,000 costs.
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