Melbourne City has set up a first-time A-League Grand Final with two Victorian representatives after an extra-time epic against Adelaide United, with the defending champions set to clash with their rivals and first-time finalists, Western United.

City battled Adelaide in a gruelling contest, requiring 120 minutes to down the resilient Reds outfit and go one step closer to becoming the first A-League team to earn back-to-back premierships and championships.

Former PAOK marksman Aleksandar Prijovic produced his performance of the season to launch Western United towards an amazing comeback win over Melbourne Victory, with the Green and Black side one game away from a debut club trophy.

Melbourne City-Adelaide United 2-1

A crucial extra-time winner from league top scorer Jamie Maclaren propelled City past Adelaide on Sunday afternoon, reaching their third successive Grand Final in the process.

Adelaide winger Zack Clough broke the deadlock with an inventive half-volley lob into the top left corner (48′) before winger Marco Tilio brought it level with a tap-in header that deflected off both the left post and goalkeeper Joe Gauci (74′).

Maclaren stepped up just two minutes into the first period of extra-time, guiding his finish into the bottom left, with the premiers holding their lead to yet again reach the Final.

City manager Patrick Kisnorbo praised the character of his players, outlasting their opponents in the 120-minute marathon, but he stressed there is still room for improvement.

“It was great but, when I look at the game overall, there are areas that we need to improve on. But I thought it was a well-fought, hard game between two teams,” Mr Kisnorbo said post-match.

Melbourne Victory-Western United 1-4

A stellar man-of-the-match performance from Aleksandar Prijovic (two goals and one assist) helped Western United overturn the 1-0 deficit on aggregate, thumping Victory on Saturday evening to come within a game of their first trophy win as a club.

Prijovic made it level on aggregate 18 minutes into the fixture with his headed goal before playmaker Jake Brimmer restored Victory’s lead with a fantastic free-kick goal (37′).

Prijovic stepped up again with a sliding finish after being fed with a terrific curling ball by teammate Dylan Wenzel-Halls (49′) before the Serbian striker turned provider, laying the ball up for Lachlan Wales whose deflected effort put the Green and Black outfit ahead (78′).

Victory had many opportunities but they could not find the back of the net and Wenzel-Halls made them pay with a late finish on the counter-attack (99′) to secure Western United’s place in the Grand Final.

Western United fielded Jerry Skotadis for the first 65 minutes while Victory subbed on Chris Ikonomidis for the final 18 minutes, though the star winger was unable to get his side back in the tie.

Western manager John Aloisi praised Skotadis’ efforts in the finals series, with the young midfielder stepping up for the Green and Black club when it counted most.

“Jerry Skotadis has hardly played this season, and we’ve put him in the last three finals games and he hasn’t missed a beat. It’s satisfying for not only him, but also his teammates because they see how hard he works every day and he’s wanting to learn, wanting to get better,” Aloisi said post-match.

The A-League season will now culminate in all-Melbourne Grand Final next Saturday, the first Final featuring two teams from the same city in the history of the competition.

A-League Grand Final fixture (AEST)

Melbourne City-Western United: 19.45, AAMI Park, Sat 28 May