Superstar import Alessandro Diamanti was again the difference as Western United edged an at-times feisty A-League elimination final 1-0 over Brisbane Roar at Bankwest Stadium.
Victory in their maiden A-League finals match on Sunday means United are now just one match away from emulating Western Sydney Wanderers' achievement of reaching the grand final in their inaugural season.
Next up for Mark Rudan's men are neighbours Melbourne City at the same venue of Wednesday evening.
Diamanti curled a sumptuous curling 25-metre free-kick inside Roar goalkeeper Jamie Young's near post on 21 minutes for the only goal of the contest.
United had barely got into the opposition penalty area up until that point but they looked far more comfortable once in the lead against a youthful Roar side with limited finals football experience.
Despite only finishing fifth, United were arguably the competition's in-form side having suffered just one defeat in their past seven matches.
The Roar had not taken the field for 13 days and they duly finished strongly, but only rarely managed to get in behind the United defence.
A Matthew Ridenton snapshot that skewed narrowly wide in the final minute of the first half was Brisbane's best effort in the opening stanza.
United fullback Josh Risdon was denied a rare goal as Young pounced on a low shot soon after the restart.
At the other end, Brisbane midfielder James O'Shea failed to make proper contact when given a clear sight of the target, with the Roar often guilty of being over intricate around the penalty area.
A rare direct run at goal saw substitute Brad Inman fire a shot against the post midway through the second half but it was the closest Brisbane came to conjuring an equaliser.