Louis Martin, aged 25, was told he had "let the sport down" when he barged into a home in Brookside, Telford, setting about his victim with two other men. The victim's girlfriend tried to break it up, but she too was struck in the melee.
Shrewsbury Crown Court heard how Martin and the victim had been involved in a dispute which prompted Martin and his associates to carry out their attack.
The trio rained punches and kicks down on him as well as stamping on him during the assault on October 22, 2020. The victim was also hit with a broom.
The attackers left through the front door, leaving the victim out cold. The victim sustained a lump on his head as well as cuts to his shoulder and knee.
Martin presented himself to police the next day after being identified as one of the perpetrators, but refused to answer any questions.
John R. Oates, prosecuting, said it should be considered a "persistent and prolonged" assault.
Martin, of Sunnymead, Sutton Hill, Telford, pleaded guilty to assault occasioning actual bodily harm. His two co-conspirators were never identified.
Judge Michael Fowler said Martin's pre-sentence report showed he has a state of mind which suggests we have a system of vigilante justice being allowed in this country.
"We don't!" said Judge Fowler. "We have a more civilised system than settling disputes by violence."
However, he felt there is "a prospect of rehabilitation" for Martin, so handed him a 15-month jail sentence, suspended for two years.
Judge Fowler said: "He has let boxing down with this sort of behaviour." Addressing Martin, he added: "If you've got a grudge against somebody, you don't go and sort it out yourself.
"If it's words, it's only words. Violence isn't an answer to words. It was a primitive and pathetic thing to do."
Martin must also carry out 200 hours of unpaid work in the community, and do 40 rehabilitation activity days. Judge Fowler also made Martin subject of a restraining order, banning him from contacting the victim or his girlfriend for three years.