Glory did get a late goal to make it interesting, when it took a deflection off Brisbane's Jacob Pepper in the 86th minute.
Brisbane will finish sixth and play finals unless Western Sydney beat Adelaide. A draw or loss by the Wanderers and Roar will make it.
Glory finish eighth with 10 wins, two draws and 15 losses.
Roar, losing Brett Holman to a knee complaint in the 27th minute, proved advantageous. Three minutes later his replacement Henrique scored, thanks to loose Perth marking.
That came on the back of Taggart's goal for Glory when Young left his line.
Brisbane defender Jack Hingert headed a long ball into Taggart's path and he lobbed it into the open goal with Young in no man's land.
Brisbane went up 2-1 just before half-time when Kristensen had all the time in the world to finish after a good ball from Matt McKay.
Roar led 3-1 in the 52nd minute when Massimo Maccarone put through a good ball in the box to Henrique. Scott Neville let him through far too easily and Henrique had a brace.
Glory had their chances in the last half-hour but Castro's poor missed penalty summed up their season. The late own goal forced by Taggart gave them hope but it wasn't to be.
AAP
