Rotorua Boys' season is now over while Hamilton will join Christchurch Boys' High School, Auckland Grammar, and Wellington's Scots College in the top four competition being hosted in Rotorua.
Hamilton Boys' are the reigning national champions and also won the Super 8 competition this year.
When the match kicked off on Saturday, Hamilton Boys' got off to a good start scoring 10 unanswered points in the opening 15 minutes.
Matthew Lansdown kicked a penalty for the home side before James Parton barged over from close range.
Two stars from the Rotorua side stepped up to reduce the margin, starting with a big break from Ma'ake Taulahi.
He took on the line and went for one of his trademark runs.
Following his break, Rotorua strung a few phases together close to Hamilton's line and eventually gave the ball to 16-year-old Viliame Tosi.
The big No8, who still has two years left at high school, broke about five tackles before charging over to score.
Unfortunately for Rotorua, first five-eighth Taulahi had problems with his left shoulder shortly after the try and eventually left the field in the second half.
In a bizarre incident, the referee Grant Cotterell also had to be replaced after struggling with a leg injury. The touch judge replaced him for the remaining 50 minutes of the match.
Hamilton scored two more tries late in the first half to race out to a 22-5 lead. They were also denied a fourth try after an intercept was called back on the stroke of half time.
Rotorua Boys' started the brighter of the two sides in the second half. They managed to get the first penalty of the half and kicked it to reduce the margin to 22-8. That would be the closest they would come though, even after a good stretch of possession in the opposition 22m.
Hamilton scored two late tries - through Viliami Tuipulotu and Shanan Tomuri - to win the match 34-8.
Hamilton Boys' High School 34 (James Parton, Solomone Tukuafu, Matthew Lansdown, Viliami Tuipulotu, Shanan Tomuri tries; Matthew Lansdown 3 con, pen) defeated Rotorua Boys High School 8 (Viliame Tosi try; Kaleb Trask pen).