The Socceroos are through to the World Cup finals next year after beating Iraq 1-0 at ANZ Stadium on Tuesday night in their Asian Group B qualifier.
Substitute Josh Kennedy scored the winner in the 83rd minute.
The victory ensures Australia second place in Group B, and automatic qualification behind group winners Japan for next year's tournament in Brazil.
Iraq midfielder Saif Salman, who bossed the game throughout, then forced Mark Schwarzer into a huge save two minutes after halftime as the rain teemed down and the clock ticked down.
As the Socceroos looked as if they were meandering, coach Holger Osieck then introduced young gun Tom Rogic for the ineffective Brett Holman on the hour - and the impact was immediate.
Rogic had three shots in three minutes and immediately gave the Iraq defence concerns.
Then Kennedy struck, ran to the corner flag and was piled upon by teammates as the road to Rio next June suddenly cleared.
Kennedy rated the strike the most important of his career.
"I really don't know what to say - it's amazing," Kennedy told Fox Sports.
Captain Lucas Neill admitted the performance wasn't great, but it was a case of mission accomplished.
"I'm proud of everybody. It's been a really tough campaign. We've stuck at it, showed mental strength," Neill said.
"Sorry, it wasn't pretty. But we've beaten what was in front of us and pushed ourselves on to a very exciting tournament."
The result secured Australia second place in Asian Group B behind winners Japan, with the top two teams from both groups qualifying for Brazil.
Australia 1 (Josh Kennedy 83m) Iraq 0 at ANZ Stadium. Crowd: 80,523. Referee: Faghani Alireza