Tauranga No8 Caleb Aperahama opened the scoring when he charged 20 metres for a well-taken try after good build-up work from outstanding front rower Kemble Frost. The simple conversion was missed though, which was crucial in the final outcome.
Te Aute reduced the gap with a penalty and Rotorua looked certain to score after a barnstorming run from No8 Viliame Tosi led to a sprint for the line for left winger Corban Selwyn. But he was cut down by a great covering tackle from Tauranga's captain and fullback Connor Fifita.
Rotorua's lively halfback Te Ra Whata then scampered away for a try in the corner, which Te Aute converted well from touch for a 10-5 halftime lead.
Tauranga came out firing in the second half, with prop Leighton Hika crashing over for a try before a clever kick into space by Te Aute was turned into a try for winger Latu Vaeno after a fortuitous bounce.
Replacement halfback Carlos Price kicked a penalty to close Rotorua's lead to 15-13. Tauranga's back three of Fifita and wingers Ryan Carroll and Christian Kelly, the school's nationally ranked 100m sprinters, then combined in a slick move which Kelly finished well in the corner.
Price slotted the conversion expertly to put Tauranga ahead 15-10 with five minutes left but they were unable to hold out the final storming finish from Rotorua, with hooker Jesse Mason-Grant getting the final try.
Tauranga Boys' host New Plymouth Boys' High next Saturday in round two.
Tauranga Boys' College 20 (Caleb Aperahama, Leighton Hika, Christian Kelly tries; Carlos Price con, pen) Rotorua Boys' College 20 (Te Ra Whata, Latu Vaeno, Jesse Mason-Grant tries; Isaac Te Aute con, pen). HT: 10-5 RBHS.