The 46-year-old coach, who took over at Brisbane in 2009, celebrated consecutive championships in dramatic style, with Besart Berisha scoring twice inside the final six minutes to clinch a dramatic victory.

The triumph also sees Postecoglou's side become the first to win back-to-back A-League championships.

“I'm not clever enough to put it into words. It's quite overwhelming. It was another dramatic day,” Postecoglou told Fox Sports.

“Both clubs went at it for 90 minutes. Our boys just never give up with the crowd behind us. We left it late but we got there.”

On the club's recent success, he continued: “It's ridiculous isn't it. I'm just a cog in the machine.

“The players, the staff and everyone involved in the club, it's been an enormous effort. That's the pleasing thing about a time like this, you look around there's a lot of smiling faces from people who put in a lot of hard work.”

Postecoglou admitted after Ivan Franjic's 52nd-minute own goal, he wondered if it was just not going to be his side's day.

“You wonder whether it's your day. It was a real battle for us today, the conditions didn't help us and Perth worked pretty hard,” he said.

“When you concede an own goal you think 'we're going to need something pretty special to get out of it' but this team has done it time and time again.”

On his side's belief, he added: “You've got to believe you can win the competition and be successful otherwise why are we in it. You can't write the script. 

“We felt this year we were really challenged and had to go through some tough times, but this is a special group of players and they deserve the trophy again.”

The former NSL winner also explained his decision to substitute last year's Grand Final goalscorers Erik Paartalu and Henrique late in the match, for young duo Luke Brattan and Nick Fitzgerald which left a few fans scratching their heads.

“It was a real battle today and we knew it would be. With the conditions being the way it was, we weren't getting real quality ball on the mark, so it was a matter of trying to mix it up and get a dose of fresh legs on, players with some enthusiasm and I felt our three subs did a fantastic job for us,” he said.

As for his own future, Postecoglou refused to be drawn into discussing his plans at this stage.

“What's next is im going to enjoy this,” he said. “My coaching adage is live for the moment, and this is one of the good ones so we'll take it all in."