The adult–oriented event included exhibition mixed martial arts matches, made popular by the Ultimate Fighting Championship, involving children as young as eight.
"It's not like the MMA you see in the movies, or what you see on TV," said John Williams, the Canadian representative for amateur mixed martial arts.
The fights are "extremely safe," he said, because the children have "lots of equipment on."
Williams said the rules were approved by the Moncton boxing commission, but psychologist Charles Emmrys disapproves of the fighting, especially as entertainment for adults.
"Violence is exciting. That's why we have action movies, they pump us up. Children should not be pumping us up by beating each other up," he said.
"When parents are talking about encouraging kids to beat up other kids, well that's called encouraging a bully to be a bully."
But Williams argues the sport is as safe as karate or taekwondo. As a precaution, he said there were two doctors and an ambulance on site during the fights.
"There are more people who get hurt and killed in cheerleading than this," he said.
Williams, who is also a trainer, said youth fights are safe and here to stay. He hopes to one day see the sport in the Olympics.
In the meantime, Williams is organizing Provincial, Atlantic and National championships. He said children and teens will be part of all future competitions.