While the green and gold were basking in the glory of their wonderful 2-0 victory over China, two potential winners exited the tournament after two shock quarter-final results.
Iran, seen by many as having its best chance in many years of winning the trophy, fell to Iraq on penalties at the end of an epic tussle in Canberra that ended 3-3 after extra-time.
Holder Japan, which had played the best football of the tournament so far, came a cropper against a feisty United Arab Emirates side and should have no complaints after a shootout defeat in Sydney.
At the end of a pulsating encounter in which Japan was continuously defied by gritty UAE both teams were locked in a 1-1 draw.
"We played a fantastic game against Iran and we lost but today I told my players you don't always have to play very nice football," UAE coach Mahdi Ali Hassan said later.
"Sometimes you have to play with your heart and with spirit and today we worked very hard to win this game.
"Football is not always fair ... and it certainly was not fair for us against Iran but the way we defended tonight we deserved to win.
"Beating Japan is a great achievement that gives us confidence and motivation for the next game against Australia.
"Australia will provide us with another tough game. We will have a day less to prepare than the Australians but we will ttry to recover well."
Ange Postecoglou's Australians would have every right to consider themselves favourites to win through to their second final in four years.
The Socceroos were beaten 1-0 by Japan in the 2011 final in Doha, Qatar, and will leave no stone unturned in their bid to win the first men's trophy in Asia since Australia joined the AFC in 2006.
However to do so they must contain the brains behind UAE's play - midfielder Omar Abdulrahman.
He bossed the middle areas of the field in the first hour of the match with a casualness rarely seen in the tournament.
He seemed to be having a runaround at training, strolling at leisure and passing the ball effortlessly to all areas of the field.
The second half was only a few minutes old when he nonchalantly lofted a chipped pass to Al Ahmed Mabhkout but the striker's shot was blocked by Eiji Kawashima.
Japan, with Keisuke Honda heavily involved in most of its attacks, dominated possession throughout the game but Abdulrahman was more productive on the fewer occasions UAE got the ball.
The Japanese had their chances but they somehow managed to miss them, particularly when out-of-touch Shinji Kagawa hit the ball wide with the last kick of normal time.
Japan's Mexican coach Javier Aguirre paid tribute to his players.
"I am very proud of my team's performance," he said.
"We gave everything we had for 120 minutes but when the game went to penalties it became a 50-50 lottery.
"We were the better team in all aspects of the game including attack.
"We showed a fighting mentality today and we need to keep this attitude in the future."
Aguirre is not expected to retain his job after this unexpected defeat.
