United hung tough over Melbourne City before Ben Halloran found an 119th-minute winner in Adelaide on Sunday night.
The win was Adelaide’s first finals triumph since their grand final success in 2016.
But now comes the most formidable task in the A-League, a trip west to Tony Popovic’s premiers Perth.
United’s clash with the Glory begins the semi-finals on Friday, with Sydney FC hosting Melbourne Victory on Sunday to decide this year’s grand finalists.
Not only do the Glory have the best record in the league and the benefit of a week off and home ground advantage, United will be weary after their two-hour slog with City.
Given the Reds have just a five-day break, coach Marco Kurz agreed he would need to modify the club’s schedule this week.
“We cannot train a lot. The focus must be to recover as well as they can, make the most rest they can and we’ll see how good shape we are in on Friday,” he said.
“(Perth) are in a better position. They had a week off. They don’t have to travel. The game is on Friday, I don’t know why but it is.
“We’ll need a fantastic game … but the boys are fit enough to play a good part in Perth.”
United are one of just three teams to have visited HBF Park this season and avoided defeat; the others being Western Sydney and Melbourne Victory.
Against City, Adelaide had several superb contributors who could threaten in Perth.
Goalscorer Halloran was a threat throughout, Craig Goodwin showed glimpses and Isaias was his usual busy hand in midfield.
Former City captain Michael Jakobsen anchored the backline and keeper Paul Izzo was superb throughout, producing a world-class save to deny Shayon Harrison.
“The team is the star, not Paul but Paul was an important part today,”
Kurz was emotional upon seeing Halloran stroke home and when the final whistle rang as the coach is leaving the club at year’s end.
The 49-year-old has agreed not to extend his contract, citing philosophical differences with chairman Piet van der Pol.
“After the game it was not easy for me. I always like to coach here,” Kurz said.
“It was a fantastic goodbye … now my focus starts on the next game.”
The other semi-finalists, Melbourne Victory and Sydney FC, have a very different preparation.
Both teams are in South Korea on Asian Champions League assignments, though Victory have left eight senior players behind as they prioritise domestic success.
Want to comment?
Send us an email, making it clear which story you’re commenting on and including your full name (required for publication) and phone number (only for verification purposes). Please put “Reader views” in the subject.
We’ll publish the best comments in a regular “Reader Views” post. Your comments can be brief, or we can accept up to 350 words, or thereabouts.
InDaily has changed the way we receive comments. Go here for an explanation.
Make your contribution to independent news
A donation of any size to InDaily goes directly to helping our journalists uncover the facts. South Australia needs more than one voice to guide it forward, and we’d truly appreciate your contribution. Please click below to donate to InDaily.