Christopher Isles was taken to Ballarat Health Services Base Hospital with serious facial injuries after he was "king hit" in Callow St, Ballarat, on September 26, 2003.

The 20-year-old was later transferred to the Geelong Hospital, where he underwent surgery for a broken jaw, fractured cheekbone and damaged eye socket.

Sammie Barry Souied, 19, of Curnow St, pleaded guilty in the County Court at Ballarat to one count of recklessly causing serious injury.

The court had heard Mr Isles had just arrived at his girlfriend's house after finishing his shift at the former Extremity Bar when he was confronted by Souied and another man in the street about 4.15am.

The pair, known to the victim, accused Mr Isles of going through one of their friend's personal belongings while she was away at the snowfields.

The friend had been a housemate of Mr Isles.

Defence counsel Russell Hamill told the court his client was unemployed, drinking heavily and "angry with the world" when he assaulted Mr Isles.

But Mr Hamill said Souied had made significant advances in his life since the offence, gaining a plastering apprenticeship, reducing his alcohol intake and increasing his involvement with his religion.

Mr Hamill said while Souied's offending was serious, he invited the court to consider imposing a suspended jail sentence.

He said Souied had never spent time in custody and had not been in any serious trouble since the assault.

But Crown prosecutor Tom Gyorffy yesterday said the offence called for a custodial sentence.

"It's an act of vengeance, seeking out a victim and then king hitting them," he said.

"It's a very serious offence and one that would warrant, call for, a custodial sentence."

Judge Wendy Wilmoth agreed, describing the assault as very serious and forceful.

"It was not an opportunistic or spontaneous attack in so far as the confrontation ... was premeditated," she said.

But Judge Wilmoth said Souied had been assessed as suitable for a youth training centre order and sentenced him to six months' detention in a YTC.