But Benjamin Burnell's dream of becoming a youth worker could be in tatters after the conviction.

Burnell, 26, was sentenced in the ACT Magistrates Court in Tuesday on one charge of common assault over the attack on Bunda Street in July last year.

CCTV footage of the incident shows Burnell deliver 12 blows to the victim as he chased him around the Civic intersection.

Burnell then pushed the young man to ground and kicked him in the head, knocking him unconscious.

Burnell then fled, leaving the victim lying in the road, and attempted to change his appearance by putting on a beanie and pulling up his hood.

The court heard the incident had been sparked when the victim danced near Burnell and his friend and a comment had been made about a hair style.

Magistrate Peter Dingwall said the jocular comment had been taken the wrong way by the offender, who reacted with a "disproportionate response".

Burnell had asked the court for a non-conviction order, as a conviction would threaten his ability to pass the background check he needed to do youth work.

At a sentencing hearing last week, defence lawyer, James Maher, said his client wanted to use his experience to teach young Canberrans.

But prosecutor Anthony Williamson pushed for Burnell to be jailed, saying he had shown no remorse and the crime had been in the "worst case scenario" for a common assault charge.

Mr Dingwall disagreed with both defence and prosecution submissions, which he said fell at two extremes of the spectrum.

The magistrate said a jail sentence would not be appropriate.

But he could not grant a non-conviction order as the "prolonged and continued assault on a defenceless man" fell at the upper end of the range for the offence.

The court heard Burnell had no prior criminal history and references portrayed him as a man regarded as well-behaved.

The references said the assault had been out of character.

The court also heard Burnell suffered post-traumatic stress disorder and anxiety, but the illnesses had no bearing on the offence.

Mr Dingwall sentenced the offender to a one year good behaviour order and 80 hours community service.

The magistrate also ordered he pay $125 in court costs and victims of crime.

It is understood the prosecution could appeal the decision to the ACT Supreme Court.