The Reds took the lead through an opportunistic Fabian Barbiero goal in the seventh minute before vice-captain Lucas Pantelis doubled the advantage early in the second half.

Adelaide United has little to play for next week but the victory, its first since Round 18, does mean it can avoid the wooden spoon if Central Coast fails to win its remaining games.

The result also means the A-League's top-six has been confirmed with a round to play.

It was a disappointing effort by the Roar which had everything to play for - the second-half send-off of captain Matt McKay inflicting further pain for the visiting side.

United took the early lead after Mathew Leckie whipped a ball back into the danger zone from close to the end line.

Barbiero was there to meet the ball and got good elevation to beat goalkeeper Matt Ham from close range.

It's the second time the 25-year-old Red has scored against Ange Postecoglou's team this season.

The Reds increased their lead in the 51st minute thanks to a clinical strike from Pantelis on the edge of the box.

His opportunity was set up by some steady possession which saw Leckie, Barbiero and Adam Hughes link up and a deflection off a Roar defender create some space for the experienced campaigner.

Pantelis, who is considering a change of clubs after the Reds' Asian Champions League campaign, dropped to his knees and outstretched his arms in a salute to the 8244-strong crowd.

Apart from the early goal, the first half produced some scrappy play.

Adelaide was well served by Pantelis and Scott Jamieson on the left side but too many of their crosses were low and defendable.

Leckie was also busy as the lone man up front but the home side lacked penetration when he was out of position.

Brisbane's attacking game lacked potency too with its four corners for the half causing little grief for the opposition's defence.

But the Roar did have its moments with Tommy Oar's 30-metre strike in the 33rd minute threatening the goals before Reds goalkeeper Eugene Galekovic punched the ball out of play.

Henrique and Reinaldo were also trying hard to find an equaliser but they squandered limited opportunities before struggling to have an impact later in contest.

Brisbane made a promising start to the second half with Ivan Franjic making a long midfield run before pulling the trigger with a clean but inaccurate strike.

However, its challenge was short-lived after Pantelis doubled Adelaide's advantage.

Apart from the goals, the introduction of new recruit Marcos Flores was a highlight for the Reds.

He distributed a couple of clever passes and caused some problems for McKay with smooth moving.

The Roar skipper was sent off in the 82nd minute after receiving two yellow cards for bringing down the Argentine with over-enthusiastic tackles.

The Roar had one last chance to peg one back but a close-range attempt from Sergio van Dijk crashed into Galekovic's left shoulder.

Adelaide United 2 (Barbiero 7', Pantelis 51')
Brisbane Roar 0
Crowd: 8244 at Hindmarsh Stadium