A chaotic final five minutes has condemned Perth to Asian Champions League heartbreak, with the Glory dropping two late goals to suffer a 2-1 injury-time loss to Ulsan Hyundai.
Youngster Daniel Stynes looked to have etched his name in Perth's history when he handed the Glory the lead - and potentially a maiden ACL win - in the 71st minute.
But Ulsan would not be denied, with Kim In-sung levelling the scores in the 89th minute and Junior Negrao snaring the victory at Education City Stadium four minutes later.
The loss is a brutal blow to Perth's hopes of progressing to the knockout stage, as they have zero points from three games and are bottom of group F with three games remaining.
Perth were on the back foot from the outset against the K League powerhouse - who featured former Glory defender Jason Davidson in their starting line-up.
Ulsan dominated the first half but were consistently met by a resolute Glory defence, with centre-back Jonathan Aspropotamitis particularly desperate.
Kim In-sung hit a chance straight at Perth goalkeeper Tando Velaphi in the 56th minute but from there the Glory remained resolute and found a foothold in the match.
Then, Stynes struck.
The 22-year-old found space at the top of the area and lashed a low, skidding shot into the bottom corner.
But Richard Garcia's Glory were unable to maintain their advantage and 18 minutes after the opener, Ulsan found their equaliser.
Yoon Bit-garam cleverly controlled a cross and knocked the ball back for an unmarked Kim In-sung to score with a well-placed strike.
Perth's Bruno Fornaroli almost reclaimed the lead in the 90th minute, forcing a superb diving save from Ulsan goalkeeper Jo Su-huk.
Then, in the third minute of injury time, Kim In-sung turned provider, looping a clever cross from the left into the path of Junior, who coolly volleyed home the winner.