Holding a 3-1 lead heading into the final five minutes of the first half thanks to a Nikola Mileusnic brace and an 18th minute Riley McGree effort, the Reds appeared to be cruising on Australia Day – their physical dominance clearly pushing United back on their heels.

But Besart Berisha’s second of the day in the 43rd minute gave the hosts some life and, when Alessandro Diamanti struck to bring things level in the 54th minute, it seemed that, somehow, Western were priming themselves to steal a game in which they had clearly been second best.

But coming to the rescue for his side, substitute Nathan Konstandopoulos fired an outside of the box effort beyond Filip Kurto in the 78th minute to secure all three points for his side.

The win propels Adelaide up to fifth on the A-League table at the end of the round, leapfrogging United in the process.

They will return to the City of Churches next week to host Melbourne City before heading up to Queensland to take on Robbie Fowler's resurgent Brisbane Roar.

United will head to the Hunter to take on Newcastle Jets next Saturday, with a bye to follow the week after.

In a sign of things to come, both sides were able to create chances early doors on Sunday afternoon.  McGree got proceedings going with two quick-fire shots that were saved in the opening minute.

Looking to return fire, Berisha scuffed a chance in the third minute after being played through by  Diamanti, who started for Western despite being forced off with an injury in his side’s 3-0 win over Central Coast Mariners the week prior.

But, dispensing with the foreplay, the Reds took the lead in the ninth minute when Blackwood ducked and weaved to win a yard of space off Jonathan Aspropotamitis and sent a cross into the box that Filip Kurto parried directly into the path of Mileusnic, who promptly fired home.

Yet that lead only lasted three minutes before Western brought things back level; Max Burgess turning Ben Halloran and leaving him in his dust as he advanced toward goal before finding Berisha in space in the area.

Though the Kosovan international took his time, he eventually pulled the trigger to brings things level.

The newfound sense of parity, however, lasted all of three minutes itself; Adelaide retaking the lead in the 15th minute when James Troisi bundled over Jerry Skotadis and released Blackwood forward with a pinpoint ball behind the Western lines that the 22-year-old sprinted onto in the area and slid across to Mileusnic, who fired into the roof of the net.

The action coming thick and fast, it was 3-1 in the 18th minute after Halloran picked out McGree to fire past Kutro after he recovered from an initial heavy touch.

Just a week after they had cruised to a straightforward win over the Mariners, Western was struggling to get anything going against their South Australian opposition - hopelessly outclassed in the midfield by the speed and strength of the Reds.

Nonetheless, they were somehow able to hang on and, even more incredibly,  peg one back just before the halftime whistle after Connor Pain, following a clever little one-two with Burgess, burst into space on the left flank and picked out Berisha inside the six-yard box for a tap in finish.

Michael Maria sprinted through the Western lines to create the first chance of the second stanza in the 50th minute, but was unable to pull the trigger in time as the United defence converged on the edge of the penalty area.

Then in the 53rd minute, against all the rhyme or reason from the first half, Western brought themselves level when Skotadis, after pouncing on a loose ball following a Berisha tackle, picked out Berisha in the area in the Italian international fired a left-footed effort home.

While they weren't as poor as they had been in the first half, Western had no right to be in the game and in a moment of cosmic justice Adelaide was able to re-take the lead in the 78th minute.

In space, substitute Konstandopoulos curled an outside-of-the-box effort inside the post after seizing upon Western’s failed attempt to clear a McGree ball into the area to ensure all three points would be leaving with the side in red.