NORTH Melbourne board member Glenn Archer has been convicted of assaulting a runner at his son's junior football match in Melbourne and ordered to pay compensation to replace the victim's broken glasses.

Despite pleading guilty to assault, the dual premiership player says he will appeal the penalty, claiming he was not judged on the full story.

Archer admitted in Heidelberg Magistrates' Court on Friday to assaulting runner Jamie Chilcot at the suburb's football ground on June 25.

The 44-year-old was fined $2000 and ordered to pay $955 to replace the victim's prescription glasses that broke in half during the clash.

"It is an abhorrent thing to do," Magistrate Cathy Lamble said as she convicted Archer.

"It sets such a bad example for children playing sport."

Archer was watching his son Jackson play in the under-15s for Park Orchards Sharks and ran onto the field when a scuffle broke out between two players.

About five minutes later, when players and officials left the ground at half-time, the North Melbourne board member clashed with Chilcot, whose job it was to deliver instructions from the opposition coach during the game.

"The accused punched Chilcot, striking the right side of his face, which startled him and the force of the blow caused the arm of the glasses he was wearing to break off," prosecutor Matt Toohey told court in an agreed set of facts.

Archer appeared frustrated he didn't get to share his side of the story.

"Don't I get to defend myself? You haven't got the full story," he said at the end of the hearing.

"The decision's been made, Mr Archer," the magistrate replied.

Parents should never run onto the field at their children's sporting events, Ms Lamble said.

"They should leave it to the umpires and other officials on the ground."

Outside court, Archer, wearing a navy suit and glasses, said he would appeal the penalty.

"I actually find it crazy that someone can read out three per cent of a story and then you're judged on that," he told reporters.

North Melbourne released a statement, saying the club has "accepted Glenn's version of events and acknowledges he has taken full responsibility for his actions and is unreservedly apologetic."

"The club will take no further action and, from its perspective, considers the matter now closed.

"Glenn is able to continue his role as a director.

"The club further understands Glenn is planning to appeal the severity of the penalty and, as such, it is not in a position to make any further comment."

The famously courageous defender was named in North Melbourne's Team of the Century and won the 1996 North Smith Medal.