An IRB rule prevented the playing of extra-time in the national 1st XV rugby competition final between Scots College and Hamilton Boys' High School.
The laws for under-19 players state a game must not go to extra-time if a match is drawn. The game in Rotorua ended 26-26, with both teams declared co-national champions after 70 minutes.
Hamilton Boys' have been in this position before, having drawn the 2008 final with Auckland's De La Salle College.
Tournament organiser Jim Lonergan said the rule was in place for safety reasons.
"They're teenagers, by the end they're stuffed. If we put on another 20 minutes there could be major injuries," said Lonergan.