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.
In knockout games, the team that scores the most tries is the one that moves on to the next round.
Scots and Hamilton Boys' scored four tries, with Scots moving on to represent New Zealand at the Sanix world youth tournament in Japan after scoring the first try.
Hamilton Boys' were aiming to return to Japan to defend the championship they won in May.