After delivering a forceful blow to the head of his victim, Sione Fonokalafi danced around with his hands in a fight stance before running away.
The blow immediately knocked his victim unconscious and he fell to the ground, hitting his head on the pavement.
Communities were sick of random alcohol fuelled violence by young men, County Court Judge Scott Johns told the 20-year-old on Friday.
There were catastrophic and ongoing consequences for the victim, who suffered a skull fracture, ruptured eardrum and hearing impairment as a result of Fonokalafi's unbridled street violence, Judge Johns said.
Fonokalafi had been out drinking with friends before the incident in suburban Melbourne about 1am on March 20 last year, and claimed he and his group had shared 20 or so jugs of beer.
There was a dispute, or a perceived dispute, between the group and the victim, the judge said, and a fight broke out.
The victim had already been set upon by others in the group when Fonokalafi came up from behind and struck the right side of the man's head.
"He had no opportunity to defend himself from the attack or indeed prepare himself in any way for it," Judge Johns said.
"It is not uncommon in the courts to see actions such as yours resulting in death or permanent disability."
Fonokalafi bounced around in aggressive, fight-like stance for a few seconds before running from the scene.
He pleaded guilty to recklessly causing serious injury and affray, and was jailed for 18 months.
It was almost inescapable the New Zealand man's visa would be cancelled upon his release, the judge added.
With time served Fonokalafi will be free within days. He was also placed on a nine-month community corrections order.