Two first-half goals to the Reds set up the victory, with Bruce Kamau's clinical finish from close range and a magical free-kick from Isaias putting the home side in complete control.

The Wanderers fought their way back into the game during the second half and grabbed one goal back through right-back Scott Neville - only to see United forward Pablo Sanchez seal the game in the dying moments.

Suffering their third grand final defeat in four years was clearly a tough pill to swallow for Popovic, who will again wonder what he must to reach the pinnacle of the domestic game.

"We weren't happy with the first half because we weren't ourselves and if we're going to lose a final, we have to lose the way we want to play," he said. "In the second half it was much better and we had a few more moments but in the end they were able to get the third.

"But I'm just so disappointed in our first half. I'm disappointed because we didn't do enough and it became too difficult to claw back the two goals."

But Popovic denied the idea that his side were outplayed by the hosts, reckoning the Wanderers closed down the space through the middle, forcing Adelaide into hitting long passes. It was there he felt the hosts gained a crucial advantage.

"The goals they scored were from easy mistakes. We didn't deal with the second ball. They didn't play football. They didn't play out from the back, they played long and forward," he said. "They kept playing long ball, so I'm not sure what we could have done [tactically]. But we didn't deal well with those balls."

The coach said he didn't have much to say to the players in the immediate aftermath but said they had plenty to look forward to next year.

"It's never nice losing a final but you've got into a final to win one. We've made three grand finals in four years, and won an Asian Champions League, so we're doing OK as a club," he said. "We're in the ACL next year, so it's not too bad. We didn't manage to win but we'll be back again next year."

Popovic said there was only one way to silence the critics regarding the side's poor record in domestic grand finals.

"We've got to win one. Everyone time we're in one, you guys will ask the same question. We'll do everything we can to get another shot at and we'll do everything we can to be celebrating like Adelaide," he said. "​We'll keep striving. We don't hide the fact we want to win everything. We wanted to win this title at the start of the year and apart form tonight it's been a fantastic season. We're heading in the right direction, that's for sure."

Adelaide coach Guillermo Amor was thrilled to see his side put together a near-perfect display on the biggest stage.

"It's a special day. A special day to win a final. It's different to when you're a player but this moment is beautiful," he said. "As a coach, you suffer more than as a player - it's impossible to touch the ball, you only have your voice.

"But in this moment, I am so pleased. So pleased for my team because they are special players, coaches, staff and supporters. I am happy for all of them. This moment, we must enjoy."

Amor said he briefly had some nerves when the Wanderers pulled a goal back in the second half.

"It's not easy to win but we are here and we've won. I think we played very well. The first half for me [was excellent]. We had control of the first half," he said. "But we know Western Sydney are a strong team and they showed that all season.

"After 2-1, in this moment, they pressed and recovered and controlled, but we had waited for our chance and in the last moment, we got our third goal."

Asked what he thought of Popovic's view that his side won by playing long-ball football, Amor was flabbergasted - looking blankly to Isaias, who sat next to him at the press conference.

"This is the best players of the game. He was the number six," Amor said. "Marcelo [Marcelo Carussia] was fantastic, for the goal, as was [Stefan] Mauk and Sergio [Cirio]."

Isaias couldn't put into words what it meant for him to score such a superb - and important - goal for his side.

"I don't what to say. I was in a good position and I took it. The last few free kicks, I did very well [at free-kicks] and I was lucky. It was a beautiful goal," he said. "It's the most special moment in my career and it's the biggest trophy we can get. I'm so happy for everyone."

Although the Barcelona legend admitted during the week that the off-field commitments in the lead-up to the grand final were somewhat distracting, Amor said his side handed the big day as well as could be hoped.

"I know what it means [for this city] - it's such a big day for Adelaide," he said. "It was a special week, everyone screaming "Come on!" on the streets. Then today, the stadium was full and supporters were fantastic."