Glory exited the FFA Cup at the Round of 32 stage as Kwame Yeboah struck in the final minute of extra-time to seal a dramatic 2-1 win for Western Sydney Wanderers at Dorrien Gardens.
The two sides had been locked at 0-0 after 90 minutes and it wasn't until the second-half of extra-time that Wanderers substitute Mohamed Adam bagged the first goal of the night.
Glory replied almost immediately through Tomislav Mrcela, but in a frenetic finale, Yeboah forced the ball home from close range to ensure that it would be Markus Babbel's men heading into the Round of 16 and when tempers frayed after the final whistle, home defender Ivan Franjic received a red card for dissent.
While naturally disappointed with the defeat, however, Glory Head Coach Tony Popovic drew plenty of positives from the performance of his side which was missing a number of of last season's regular starters.
"You always go into every game wanting to win and we had enough chances to score," he said.
"We created some good opportunities and had some good passages of play, which was pleasing and their 'keeper made some very good saves.
"In the end it was very tight. We fought hard after going 1-0 down, but then they got the decisive goal.
"We had a lot of young players in the team who got some valuable minutes and gained some great experience.
"It was a solid beginning for Nick D'Agostino and we got Diego [Castro] on the park as well.
"So there were a lot of positives and good signs.
"We were pleased with the performance and the fighting spirit they showed and we know we'll get a lot better.
"We would have loved to have gone through, but it wasn't to be."
Bruno Fornaroli fired a shot across Wanderers' bows after six minutes as the game got off to a lively start and the Uruguayan was not far away from meeting Chris Harold's low ball that flashed across the face of goal moments later.
Harold was also involved in Glory's next chance, looping a cross-shot narrowly off-target having been released by a fine ball over the top from Neil Kilkenny.
As the hosts continued to press, Wanderers 'keeper Daniel Lopar was forced into an impressive save with his feet after Tass Mourdoukoutas intervened to prevent a Joel Chianese cross from reaching the lurking Fornaroli and almost inadvertently sliced the ball into his own net.
Next to go close for Glory was Harold whose shot on the turn from just inside the box was parried by Lopar, while shortly afterwards at the other end, Daniel Georgievski drew Liam Reddy into his first meaningful save of the night with a stinging, 25m strike.
The final action of the half, meanwhile, saw Brandon Wilson rise highest to meet a Kilkenny corner only to power his bullet header over the bar.
Kilkenny was also involved in Glory's first chance of the second half, fizzing a well-struck free-kick narrowly over, before Georgievski replied in kind for the New South Welshmen, rushing his shot when well placed.
The chances continued to flow as the half wore on, D'Ágostino seeing his low shot tipped wide by Lopar after Fornaroli's persistence had fashioned an opening.
As he continued to impress on his competitive debut for the home side, Fornaroli almost teed up substitute Diego Castro with another clever ball into the box, but ultimately neither side was able to find a way through in the regulation 90 minutes.
Extra-time opened with Wanderers Adam firing an angled strike over the crossbar having burst away down the right channel and then forcing Reddy into a fingertip save with another fierce shot from just inside the box.
Adam was not to be denied four minutes into the second period of extra-time, however, finding a pocket of space on the edge of the box and rifling a low shot into the bottom corner.
Undaunted by that blow, Glory continued to press and within three minutes were back on level terms when the ball fell for Mrcela 12m out and he thumped an unstoppable half-volley past Lopar.
The late drama continued unabated as a low cross into the box flashed through a crowd of players and fell for Yeboah who slid the ball home from point-blank range, sparking wild celebrations among the Western Sydney players and staff alike.
FFA Cup Round of 32
Perth Glory 1 (Mrcela 112') Western Sydney Wanderers FC 2 (Adam 109', Yeboah 120')
Referee: Adam Fielding
Assistant Referee 1: Josh Mannella
Assistant Referee 2: Arvin Shanmuganathan
Fourth Official: Shane Skinner
Perth Glory: 33.Liam REDDY (gk), 3.Jacob TRATT, 5.Ivan FRANJIC, 7.Joel CHIANESE (21.Trent OSTLER 104'), 10.Bruno FORNAROLI, 14.Chris HAROLD (28.Gabriel POPOVIC 90'), 15.Brandon WILSON, 16.Tomi MRCELA, 18.Nick D'AGOSTINO (17.Diego CASTRO 67'), 20.Jake BRIMMER, 88.Neil KILKENNY
Substitutes not used: 1.Tando VELPHI (gk), 31.Daniel WALSH
Yellow cards: Tratt, Chianese
Red cards: Franjic 120'
Western Sydney Wanderers FC squad: 1.Daniel LOPAR (gk), 4.Dylan MCGOWAN, 5.Daniel GEORGIEVSKI, 6.Kosta GROZOS (22.Nicholas SULLIVAN 20') ( 35.Mohamed ADAM, 71'), 10.Radoslaw MAJEWSKI, 11.Bruce KAMAU, 13.Tass MOURDOUKOUTAS, 17.Keanu BACCUS, 19.Pirmin SCHWEGLER, 21.Tarek ELRICH, 27.Kwame YEBOAH (33.Tate RUSSELL 120')
Substitutes not used: 29.Daniel WILMERING, 40.Nicholas SUMAN (gk)
Yellow cards: Schwegler, Majewski
Red cards: None