Substitute Josh Kennedy's goal seven minutes from time sent Australia into the World Cup finals in Brazil next year after a 1-0 defeat of Iraq in front of 80,523 at Sydney's Olympic Stadium.
Kennedy, who has struggled with a knee injury since last playing for the Socceroos in 2011, replaced a displeased former Everton star Tim Cahill in the 77th minute before climbing unmarked to head Mark Bresciano's cross past the despairing dive of Noor Sabri.
Kennedy was mobbed by his team-mates as the Australians celebrated the goal that effectively sealed second place in Asian qualifying Group B and a ticket to their fourth world finals after appearing in 1974, 2006 and 2010.
"It's amazing for the country," delighted captain Lucas Neill said. "Three World Cups (in a row) now. It wasn't pretty but we beat what was in front of us. Tonight let's look at the positives, Australia are going to Brazil!"
Mark Schwarzer kept another clean sheet after Robbie Kruse found the net with a fierce 65th-minute shot in a tense encounter but the 'goal' was disallowed for a Cahill push.
Home nerves were finally lifted by Kennedy's late intervention before Iran and South Korea joined Australia in next year's finals after a 60th-minute goal from Reza Ghoochannejad earned the former a 1-0 victory in Asian Qualifying Group A in Seoul.
The result was enough to send both sides to Brazil as Uzbekistan, who needed to beat Qatar by seven clear goals, had to settle for a 5-1 victory.