Initially, the pair wrestled and pushed each other but the situation calmed down after security staff threatened to have the defendant removed from the site.
Having been persuaded to let Warner remain on site, Mr Young and his attacker returned to their caravan but the defendant became outraged once again and severely beat the victim until he was unconscious.
The victim, who also suffered a torn lip, had to take four months off work.
A sentencing hearing at Cardiff Crown Court on Friday heard Warner took offense at a comment made by Mr Young’s partner regarding his children.
Prosecutor Josh Scouller said: “The two men stayed up drinking while the children [and partners] went to bed.
“Mr Warner reignited the argument about the comment made about his children. Mr Young asked if they could deal with it in the morning but the defendant punched Mr Young to the face whilst holding an e-cigarette.
“Mr Young fell to the floor and was set upon, punched repeatedly and kicked to the body and stamped on at least twice. Mr Young felt his jaw crunch on the second stamp and he lost consciousness.
“The next memory he had was waking up in intensive care at the University Hospital of Wales.”
As a result of the attack, Mr Young suffered fractures to his jaw, nose and hyoid bone, a cut lip, and various cuts and bruises.
“In a victim impact statement, Mr Young said his life had been affected in a negative way having suffered permanent nerve damage which caused him difficulties eating and drinking.
“His employment had also been affected having been forced to take four months off his job as a supervisor of railway workers.
The victim added: “My personal life has been affected and I don’t go out drinking and socialising. I’m fearful of being assaulted if I go out and I suffer from depression…
“I struggle to sleep and I am a shadow of my former self…I am fearful of Shaun and do not wish to see him again.”
Warner, of Susannah Place, Cardiff Road, Treharris, was found guilty of causing grievous bodily harm with following intent a trial.
The court heard he had previous convictions including affray, common assault and using threatening/abusive/insulting words or behavior.
In mitigation, Stephen Thomas said his client was remorseful and accepts his behavior was “wholly unacceptable”. He described the defendant’s actions as “an outburst of drunken violence” after losing control.
Sentencing, Judge David Wynn Morgan said: “This was a frenzied and violent attack which resulted in grave injuries.”
Warner was sentenced to five-and-a-half years imprisonment, minus 128 days served on tag. He was also made subject to an indefinite restraining order.
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