A ground-record 44,085 fans packed into Allianz Stadium on Saturday night to see the reigning European champions hold off the Wallabies in a gripping series finale laced with drama and controversy.
The Wallabies were sensationally dudded by a controversial TMO decision after the 80-minute siren.
Wallabies captain David Pocock was left incredulous when the referee told him the game was over with Ireland ahead 20-16.
The incredible series — which has seen Ireland win the Landsdowne Cup 2-1 — ended in absolute shambles when the TMO failed to make a decision that Irish player Jacob Stockdale had deliberately stuck out his hand to stop Bernard Foley passing to three un-marked Wallabies players on the wing.
The incredible finish saw the Wallabies desperately attacking in the 81st minute, needing a try to snatch a dramatic win.
They appeared to be on the verge of a famous win when Foley took the play to the right wing and created a four-on two for the Wallabies' right edge.
He stepped one defender and then tried to throw a pass to Dane Haylett-Petty on the wing, but his pass was cut-off by Stockdale and the ball drifted over the sideline behind three Wallabies players.
Stockdale had stuck out his hand and there was enough evidence for the referee to send the decision to the TMO with a suspected cause for a yellow card and a deliberate knock-on from Stockdale.
That's where the game descended into farce as the TMO judged there was not sufficient evidence to overrule the on-field decision, despite replays showing Stockdale clearly played at the ball.
The TMO declared there was not enough evidence to rule conclusively that Stockdale had deliberately attempted to hit the ball.
The third official acknowledged Stockdale had clearly touched the ball, but wasn't prepared to issue a penalty for it — despite his reach proving the be the most decisive play of the game.
"This has ended in farce — it ends in controversy," Network 10 commentator Gordon Bray said.
Wallabies coach Michael Cheika said he had to spend extra time in the coaches box to try and calm down before his post-match interviews — such was his disappointment at the referee decisions.
"I don't understand it sometimes," he told Network 10.
"Some things didn't go for us. You need a few things to go for you in a game.
"It could have gone either way. It was pretty tight. I really feel for our supporters who came out here tonight.
"It was an electric atmosphere and I promise you we'll be back for the next (Bledisloe Cup) series against New Zealand in better shape and we'll be trying our best to make them proud."
Cheika was visibly furious throughout the match, as French referee Pascal Gauzere made a series of bewildering decisions against the home side, allowing Jonny Sexton to ultimately boot the Irish to a famous victory through five penalty goals.
Flanker and man of the match CJ Stander scored Ireland's only try in the 45th minute, before winger Marika Koroibete replied with Australia's lone five-pointer shortly after to cut the visitors' lead to a point and set up a grandstand finish.
A late Sexton penalty goal gave the visitors a touch more breathing space but there were hearts in the mouths of every men in green right up until the fulltime whistle. The television match official (TMO) agonised over a possible intervention in Australia's favour in the final minute.
After several minutes, the TMO eventually decided there was inconclusive evidence to penalise winger Jacob Stockdale for a deliberate knockdown that would have given the Wallabies one last attacking chance in front of the posts. Ireland's victory, a week after they levelled the series in Melbourne with their first Test win in Australia in 39 years, consolidated their world No.2 ranking and denied the Wallabies a first three-Test series win since beating the British and Irish Lions in 2002.
