"I thought to myself what would I want when I was 10 - a day off school and a bit of rugby.
"Luckily, the police came on board."
The event is designed by police to encourage youth participation in sport and healthy lifestyles.
Schoolchildren mimic World Cup-style rugby with a parade of the represented nations before getting stuck in to the action.
Mr Riwai-Couch said yesterday's event was like any other staged during the last six years.
"When play gets under way it's all go," he said.
Martinborough School, representing Samoa, eventually clinched the win, 10-8 in a close final against Solway School, which represented Romania.