Iraq will meet the Socceroos' conquerors, Korea Republic, in an Asian Cup semi in Sydney after Salam Shakir's spot-kick gave them an incredible 7-6 penalty shoot-out win over Iran in their Asian Cup quarter-final.
Defender Shakir held his nerve to score the winning penalty after the two teams were locked at 3-3 following 120 minutes in Canberra.
Iraq - winners of the tournament in 2007 - will now play South Korea on Monday, with a spot in this year's final up for grabs.
Both sides made a stuttering start to the shoot-out, as Iran's Ehsan Hajsafi and Iraq's Saad Abdulameer missed the target.
The next 12 penalties were scored, though, including a Panenka from Iraq captain Younis Mahmoud at 4-3 when a miss would have eliminated his side.
Mahmoud's bravery was made more amazing by the fact he missed a similar penalty in his side's 2-0 win over Palestine on Tuesday.
Iran's Vahid Amiri then hit the post, allowing Shakir to slot to his right and secure Iraq's progression.
Earlier, Sardar Azmoun's header gave Iran a 24th-minute lead, before Williams, who was criticised heavily by Iran boss Carlos Queiroz earlier in the tournament - leading to the ex-Real Madrid coach being fined - sent Mehrdad Pooladi off in bizarre circumstances just two minutes before half-time.
Pooladi, earlier booked for a late challenge on Ahmed Yasin, made minor contact with Iraq goalkeeper Jalal Hassan Hachim when chasing a loose ball.
The keeper then shoved Pooladi, who theatrically fell to the ground holding his face, leading to another booking from Williams.
Iraq made the man extra count in the second half, when, after a spell of pressure, Yasin fired in from a tight angle 11 minutes after the restart, and after an additional 30 minutes was forced, Mahmoud headed them in front.
Iran climbed off the canvas, though, with Morteza Pouraliganji's thumping header bringing them level in the 103rd minute, but the defender then brought down Yaser Kasim in the area to concede a penalty - scored by Dhurgham Ismail in the 116th minute.
The drama, amazingly, did not end there, as an Iran corner - which was initially cleared off the line, before Andranik Teymourian fired against the crossbar - was finally nodded in by substitute Reza Ghoochannejhad in the 119th minute.
That brought about penalties but it was to be Iraq's night in the Australian capital.