With many quick to write off Phoenix's finals aspirations a resolute performance from Wellington has made for an intriguing last six weeks of the season.
After a difficult week off the pitch, Wellington made the most of a full week's preparation without travel to put in a determined performance.
In the opening minutes Wellington looked composed with Shane Smeltz prominent in his return to the starting XI.
Brandon Borello tried an early curling effort in the 8th minute, but some fine work from Adam Parkhouse saw Phoenix win a corner, which almost fell kindly for Roy Krishna.
A heavy, unsteady surface made for a slow opening twenty minutes and there was an early blow for Wellington when the hugely experience Marco Rossi limped off with a hamstring strain after an on-ball knock.
Some lovely work from Krishna gave Michael Theo a nervous moment, but the veteran 'keeper did well to hold a fiercely struck cross.
In the 26th minute Thomas Broich found himself with a golden opportunity to score but Phoenix's custodian Glen Moss saved brilliantly when one-on-one to deny the German.
Krishna was then fouled when through on goal by youngster Cameron Crestani, with the pitch also playing a hand in bringing down the flying Fijian.
But in the 31st minute Phoenix finally found the breakthrough after a superb delivery from Parkhouse picked out Smeltz in plenty of space, and the A-League's second all-time topscorer made no mistake with a diving header right into the bottom corner.
Vince Lia almost added a second spectacular strike for the season in his testimonial tenth year of service for Wellington, as he attempted an audacious chip from 55m - but Theo was able to scramble back and recover.
In humid conditions it was the visitors who finished the half with a slight spring in their step, and Barbarouses found himself in a good position to add a second, but his shot sailed harmlessly high.
In the second half Broich looked to drag the visitors back into the game, but some determined defending from Alex Rodriguez saw a fine Brisbane move snuffed out.
In the 54th minute Rodriguez almost grabbed his second A-League goal after a mazy dribble past several Roar defenders, but Theo saved well at his near post.
It was the Spaniard again lively minutes later in the middle of the field, and his ball found Krishna in space, but the Phoenix topscorer's lashed shot whistled just past Theo's post.
Wellington enjoyed a strong passage of possession and they got their reward moments later after a fabulous string of 22 passes found Barbarouses out wide, and his whipped cross was tucked home by Krishna for his 10th goal of the season.
Brisbane went to the bench and moved Matt McKay back to the centre of midfield and the Roar captain looked to urge his side.
Tratt picked up his fifth yellow card in contentious circumstances, meaning a suspension for Wellington's next game against Perth, and in the 69th minute Moss again had to be alert.
The pressure was building and Borrello pulled a goal back for the Roar with a fine curling effort from outside the box to make for a nervy finish.
Hamish Watson came on for a limping Tratt, and he had an immediate effect winning a corner with a deflected shot.
As Brisbane pushed for an equaliser chances to strike on the counter emerged. Barbarouses found Krishna with an excellent cross-field ball, before the Fijian backheeled to Smeltz. The All White striker did brilliantly to beat one, but a desperate trailing leg broke up the attack.
Parkhouse limped off injured to hand James McGarry his first start of the season with a few minutes to play in regulation time.
The Suncorp crowd tried to will their team home, and four minutes of extra time seemed an eternity, but Phoenix stood tall to send a strong message to their critics.