A DALBY man who knocked a 14-year-old boy unconscious from an
A DALBY man who knocked a 14-year-old boy unconscious from an"unprovoked" one-punch attack and then ran away has been jailed.

Dalby man jailed after one-punch attack in town

A DALBY man who knocked a 14-year-old boy unconscious from an"unprovoked" one-punch attack and then ran away has been jailed.

Minutes later, Ethan James Johnston then bashed a man who had been providing first-aid to an injured person, a court was told.

Johnston, 23, pleaded guilty in the Southport Magistrates Court yesterday to two counts of assault occasioning bodily harm.

Police prosecutor Sergeant Bob Soper said the young victim of the "unprovoked attack" on October 28 last year suffered significant pain, bruising and temporary vision loss.

"It's an appalling example of gratuitous violence, he had no reason to assault the victim," Sgt Soper said.

"He appeared to be looking for someone to engage in a confrontation with.

"He ran callously away from the scene."

Defence lawyer Jodi Allen said Johnston was a victim of assault himself that night but his attackers were not the people who hurt him.

She said he had been drinking for hours at a golf club and had no memory of hitting the boy about midnight.

"He said he becomes a different person when he consumes alcohol," Ms Allen said.

"He simply has no recollection."

Ms Allen said Johnston developed a drinking problem while on a work stint in Longreach.

He has lost desire to go clubbing since the incident and instead enjoyed alternative social outings such as barbecues with friends, the court was told.

Magistrate Andrew Sinclair sentenced Johnston to 12-months jail to be released on parole on September 26.