Next week, the Cougars play off for a spot in the grand final against league heavy-weights Swan View.
If they win next week, they will secure their third grand final berth in their three-year history.
The colts came out of the blocks and led 4.3-0.1 at the first break against Quinns.
With the run and carry at an impressive level, the Cougars extended their lead in the second, taking a 7.6-0.2 lead into the main break.
The third quarter saw the Cougars starve the Quinns forwards and really shut them down all over the ground.
This was an unbelievable quarter of football and Canning Vale took a 14.8-1.3 lead into the final change.
There were a few field adjustments at the final change, but the Cougars still won the quarter despite Quinns getting a couple of goals.
The Cougars had 11 goalscorers, and Cody Nelson and Alec Cook led the way with three goals each.
Better players on the day were Joel Holmes, Dan Roy-McGregor and Alec Cook.