Nelson College recovered from a slow start to beat the defending UC Champions in a hard-fought see-sawing game at Orangetheory Stadium on Saturday.
It was a close first half with both teams scoring before Nelson closed out the half with a last-minute try from hooker, Dylan Irvine.
St Andrew's (StAC) showcased more of their young talent in the second half with a dominant performance from NZ Secondary school flanker Torian Barnes.
StAC eventually fell six points shy of victory with a last-minute interception try from winger Jackson Foster.
"It's frustrating for us, we didn't hit the marker in terms of what we were trying to achieve," said head coach Ian Robinson.
The two sides have a fierce history in the game with both schools producing All Blacks such as Richie Mo'unga and David Havili.
Nelson College ended a 12-year drought to win the UC Championship in 2019 before StAC stole the cup the following year for the first time in the school's history.