After a scoreless first-half, Kosta Barbarouses scored the opening goal for Brisbane with a 52nd-minute strike.
Brisbane skipper Matt McKay nodded home on 73 minutes to settle the game.
Before then, former Celtic winger and New Zealand international Michael McGlinchey struck the post in the first-half after an exciting run.
And sandwiched between Roar's goals, the hosts hit the woodwork again, twice in quick succession.
But McKay's effort settled the first-leg of this major semifinal clash in front of over 10,000 fans at Bluetonge stadium.