Cruising to a 3-0 halftime lead off the back of a Jamie Maclaren brace, Adrian Luna volley and some calamitous play from United, City should have been cruising to an easy win at AAMI Park.

However, just as it seemed that United was ready to concede defeat by throwing on the kids, two pieces of catastrophic defending of City’s own gifted the victors two penalties, a one-man advantage and the most unlikely of chances to take something from the game.

That, though, is where the madness ended, City just doing enough with ten men to hold onto their one-goal lead.

Both looking to bounce back from disappointing runs of form, Erick Mombaerts and Mark Rudan rang in numerous changes heading into the fixture – resulting from both injury and form.

Coming off back-to-back defeats against Melbourne Victory and Sydney FC, Mombaerts jettisoned Scott Galloway and Harrison Delbridge from his XI alongside international call-ups Connor Metcalfe and Tom Glover and the inured Javier Cabrera and Rostyn Griffiths.

In their place stood Florin Berenguer, Javier Cabrera, Lachlan Wales, Luna, Richard Windbichler and Dean Bouzanis.

Rudan’s United made five changes to the side that lost 3-1 to Wellington Phoenix the week prior; Aaron Calver and Brandon Hamill absent thanks to injuries, Max Burgess and Dylan Pierias dropped to the bench and Scott McDonald, according to a report from The World Game, on his way to Brisbane.

In their place entered Valentino Yuel, Seb Pasquali, Apostolos Stamatelopoulos, Dario Jertec and Jonathan Aspropotamitis.

Unfortunately for Rudan, his additions – and holdovers – proved far less capable than Mombaerts in producing what was perhaps the worst first-half ever produced by the side wearing Green and Black.  

City’s first 45 was clear and incisive, creating chance after chance that – in all honesty – could have resulted in a larger lead than the 3-0 score they took into the rooms at half time.

Wales drove at an all-too passive Pasquali before putting in a ball that Berenguer – who had fired into Aspropotamitis and, in the immediate aftermath, be bundled over the line by Maclaren in just the fifth minute of play.

In the 36th minute City worked the ball across the face of the United area before Craig Noone – who had his best A-League game in a City shirt - dinked a ball over the top of the United back four for Luna to run onto and hammer home with an absolutely gorgeous volleyed effort.

The goal was perhaps made easier – if not possible – thanks to Pasquali’s willingness to watch as Luna ran past him in the hope that he would be offside – only for hoping for Aspropotamitis to play him on.

United’s more established players weren’t immune to whatever was befouled their side’s wits either; Andrew Durante and Filip Kurto producing a comical piece of defending as they, seeking to clear a Luna ball played over the top, collided with each other and allowed Maclaren to skip through and net his brace.  

For a time, it appeared as though the only silver lining to be found for United on the night would the A-League debuts handed to Thierry Iradukunda and Josh Cavallo – who both entered as second-half substitutes.

But, whether it be thanks to the injection of youthful exuberance and pace brought about by the youngsters or City reverting to type, United, somehow, found themselves right in the thick of things as the game raced toward its conclusion.

With what was his first-ever touch in senior football, Cavallo raced onto a ridiculously good pass over the top from Diamanti and knocked the ball beyond Bouzanis and, brought down by the City keeper, won a penalty that was converted by Besart Berisha in the 75th minute.

Minutes later youngster Perias, who had entered the fray with Cavallo, attempted to play a ball across the face of a sliding challenge from Delbridge that careened into the defender’s arm – winning United another penalty and giving Delbridge his marching orders for denying a clear goal-scoring opportunity.

On the balance of the first 75 minutes of play, United have never been able to force their way back into the contest they were able to do but – with Perias and Pasquali both showing signs of late-life – could have perhaps found another goal to tie it up if another five minutes could have been found.

Perhaps a small positive to take from an otherwise disappointing night.

The concern for City going forward will be figuring out what was the cause of their sudden collapse as the game wound down.

Was it the heat? Was it the smoke?

Or was it something more?