A man who Mr Withers thought was the bottom child's father "took one or two steps on to the field and pulled the child who was on his child off."
Mr Withers said he did not think the man was angry, but was reacting instinctively to the situation.
"Like any parent might in a situation where you felt your kid was being threatened, I got the impression he really didn't think and just sort of jumped in.
"It was just unfortunate it happened right at the feet of the parent. If he'd been at the other end of the field the whole thing would have blown over before he even had the chance."
The situation escalated when another man ran over and started shouting at the parent.
"The guy, who I assume was the coach of the Waitemata team, ran straight across to the father and basically pushed him away and started shouting, 'Get your hands off our kids'."
Mr Withers said the man was agitated, and kept repeating, "get your hands off our kids" when the referee tried to interject.
"He had a point, but made it perhaps a little bit more strongly than was necessary and elevated the incident."
The referee managed to calm down both parties, but not before three or four more parents had become involved as well.
"I thought the ref acted very well, he said to both parties, 'Look it's my job to deal with the situations, please parents get off the field.' He calmed the situation down very quickly."
Mr Withers said although no punches were thrown, there was "a bit of pushing," which upset the children playing.
"They were all a bit shocked that suddenly there were all these adults shouting," he said.
"I think it might have been the first time a lot of them had seen genuine adult aggression."
Mr Withers said he had been going to kids' matches every Saturday morning for almost two seasons and had never seen anything like it happen before.
"It wasn't a fight but it was an ugly incident," he said.
"Talking about it with some of the other people who had seen it, everyone concurred it was ugly and didn't need to have happened."
Mr Withers said he had made contact with the Auckland Rugby Union and offered to talk with staff about what he had seen.
Waitemata club chair Mark Mallabar told NZME. News Service earlier today that a meeting to "work through" what had happened would be held with delegates from both rugby clubs, as well as those involved and eyewitnesses, as soon as possible.
"The sooner these issues are resolved the better. You can't just let it drag on," he said.
Mr Mallabar said he and other club officials would "go all out to find out" what had happened, but said the two clubs' reports were so contradictory he did not know what to believe.
He hoped those involved had calmed down since the weekend and that all parties could reach an agreement after talking.
Auckland Rugby Union spokeswoman Libby Gudmundsson said staff were looking into the reports made by the clubs this morning and, once they had a clear picture of what happened, would talk to the people they received the reports from.
Ms Gudmundsson said a decision would follow discussions with club representatives.
"Auckland Rugby staff will be meeting with both clubs, their junior delegates and the involved coaches to discuss appropriate side-line behaviour and on-field sportsmanship.
