St Paul's kicked a penalty to get on the board then with the final play of the first half, they looked likely to run away to score until a superb cover tackle from halfback Leroy Carter.
In the second half, a fired up St Paul's side quickly closed the gap to 13-10 after a forward drive over the line.
Tauranga Boys' fullback Cole Forbes kicked a penalty to open a six-point gap which they only just held after St Paul's spilled the ball forward a metre short of the goalline.
The rest of the half was tightly contested with goal kickers swapping penalties for the final score of 19-10.
Tauranga Boys' had plenty of heroes. The powerful midfield combination of Manaia Harawira and captain Will Ngatai was a constant threat while openside flanker Flynn Kelly defended superbly around the fringes.
Tauranga Boys' have a new coaching team this season with former provincial players Dan Goodwin and Richard Apanui joining Steve Kelly.
Head coach Goodwin, who is an old boy of the school, was pleased with his team's performance.
"The belief in the boys was there. They trained really well all week and they believed in our systems and they stuck to them. That was the difference I think," he said.
Goodwin is confident he has the makings of a strong squad.
"We have a really good bunch of young men here. Each week our aim is to improve and they are improving but we are not getting too far ahead of ourselves. We will take each week as it comes.
"We have a tough game next week against either Hamilton Boys' or Rotorua Boys' that will see us well into the start of the Super Eight."
