After going 12 games without saluting at home – a run stretching back to last season that set a new league record – Sam Klein's goal after just 96 seconds put the Roar on track to finally secure an elusive victory, before Florin Berenguer added the second in the 24th minute.
Angus Thurgate teed Hiroshi Ibusuki up to halve the deficit on the stroke of halftime, but the Roar were comfortably on top throughout the contest and deserved their win.
The result marked the first time Ruben Zadkovich's side won in Queensland since they beat Melbourne Victory back on March 3, 2024.
Consigned to consecutive defeats for just the second time this season, the loss effectively ended any hope that United had of chasing down Auckland FC atop the table and leaves them nervously glancing over their shoulder at fourth-placed Western Sydney and fifth-placed Melbourne Victory.
Possessing a game in hand, Auckland only need a point from their remaining three fixtures to ensure they finish above John Aloisi's side, who will tumble from third to fifth if Wanderers and Victory win this weekend.
And while the Roar were clinical in taking their goals, United did themselves no favours.
Tate Russell, who came off at halftime with a hamstring injury, was left in no-man's land by a stutter step from Jacob Brazete before the youngster cut the ball back to Klein for the first.
A calamitous back pass from skipper Ben Garrucio then bounced off the heels of Dylan Leonard before it could reach its intended target in Matt Sutton to set Berenguer up for what proved the decisive goal.
