They were certainly up against the odds with Rotorua fielding a much bigger and older team with six players aged 19.
The visitors began in style with an early try to No 8 Kaydis Hona before Tauranga centre and captain Will Ngatai made a strong burst, to link with livewire flanker Flynn Kelly in a sweeping movement finished off by Manaia Harawira.
Rotorua's excellent fullback Kaleb Trask shows some silky skills to score and take a 14-5 lead but in the final play of the half Tauranga fullback Cole Forbes started and finished another long range raid to close the gap to 14-10 at the break.
Ngatai started the second half with another fine run and this time right winger Shi Jie Yong scored. Another missed conversion proved costly but Tauranga had the lead 15-14 and were roared on by what seemed like most of the school in support.
Trask regained the lead with a penalty before Tauranga camped in the Rotorua half.
They put some real heat on the Rotorua line before an unforced error, spilling a simple pass with a try on, changed the game's momentum as Rotorua escaped.
Two minutes later they scored down the other end through Tarzan Smith. Winger Yong charged the conversion down to keep the score to 27-18.
Typically, it was Kelly who sparked a late Tauranga raid which saw big prop Sione Afu Tuputupu score to set up a frantic final three minutes with Rotorua holding on.
Tauranga coach Dan Goodwin was proud of his team's effort but frustrated to lose such a key game.
"No doubt about it our goal was to beat them and in big games like this you only get a couple of opportunities. If you let them slip it is hard work to win," he said.
"My boys are a great team and they have worked really hard. There is no shortage of heart and there hasn't been all season.
"They have got better and better and that was the goal from the start - to improve. I really do think that today is the best I have seen them play.
"We were right in the hunt in the 70th minute."
Rotorua Boys' High School 27 (Kaydis Hona, Kaleb Trask, Tarzan Smith, Taane Paki tries; Trask 2 cons, pen)
Tauranga Boys' College 25 (Manaia Harawira,Cole Forbes, Shi Jie Yong, Sione Afu Tuputupu tries; Jake Malbon con, pen)