Lance said his client "has achieved at the highest level in coaching in his sport" and still coaches locally as an unpaid volunteer.
The coach's assault came after his then 16-year-old son was bullied at a party earlier this year.
His boy came home with a shaven head, bloody nose, fat lip and food smeared over him, the court heard.
"As a parent he was upset and aggrieved and wanted to make sure this didn't happen again," Lance said.
Later, on February 6, the coach noticed his son's bully at a sports venue and "approached him, in essence to reprimand him", Lance said.
The coach confronted the 16-year-old in an alleyway and there was a verbal argument, the court heard.
Then the coach grabbed the teen by the collar and shoved him up against a concrete wall.
The teen broke free and attempted to flee but the coach's son joined in and assaulted his bully while his father watched.
The teen suffered bruising to his head, the court heard.
"He didn't strike the boy or hit him in any other way," Lance said. "It was a rough grabbing by the collar to get his attention."
A complaint to police was the brought by the mother of the boy the coach assaulted.
Diversion for the coach was also declined by police, the court heard.
Lance said his client was a family man and when asking Judge Sinclair for permanent name suppression said: "The real reason the press are here is because it's [this well-known sports coach]."
On the bid for secrecy, the judge said: "Issues involving your son outweigh the public interest in knowing your name."
