Australia booked their place in an intercontinental World Cup play-off next month as Tim Cahill inspired them to a 2-1 extra-time win over Syria in Sydney on Tuesday.
Ange Postecoglou's side, who were held to a 1-1 draw in the first leg, secured a 3-2 aggregate victory to end their opponents' remarkable qualifying run.
Syria cancelled out Australia's away goal when they took the lead through Omar Al Soma after only six minutes, but Cahill – handed a place in the starting line-up while Aaron Mooy was surprisingly on the bench – levelled matters with a fine header seven minutes later.
The Socceroos were the dominant force at ANZ Stadium but struggled to turn their possession into meaningful chances and were often thwarted by goalkeeper Ibrahim Alma.
Syria had a man sent off early in extra time, though, and were eventually undone when Cahill powered home Robbie Kruse's cross for his 50th international goal.
They will face the fourth-place team from the CONCACAF standings, most likely Panama or Honduras, in a two-legged play-off in November, with the winner going on to the group stage of next year's finals in Russia.
Syria threatened with an early counter-attack and it was a warning Australia failed to heed, as they gifted the visitors the lead in only the sixth minute.
Poor play in midfield allowed Tamer Haj Mohamad to surge towards the penalty area and play in Al Soma, who fired high beyond Mathew Ryan and into the net.
Postecoglou's concerns threatened to deepen when Brad Smith had to go off injured, with Mooy introduced in his stead, but the Socceroos breathed a sigh of relief with 12 minutes played when Cahill headed in a brilliant Mathew Leckie cross from the right.
Calmed by their equaliser, Australia began to dictate the play and looked the most likely to score the third goal, with Leckie denied by goalkeeper Alma and Tom Rogic firing narrowly wide of the right-hand post.
Syria occasionally threatened on the break but seemed happy to sit back and hold out for extra time, with Rogic twice denied by Alma and watching another effort deflected inches wide.
Australia were given a boost early in extra time as Mahmoud Al Mawas was given a second booking by replacement referee Ilgiz Tantashev, prompting Postecoglou to throw on Tomi Juric to bolster the attack.
Fellow substitute Nikita Rukavytsya had a volley tipped over the crossbar but Cahill at last found the breakthrough with 11 minutes left, leaping high to head in Kruse's clipped cross from the left and become the first man to reach a half-century of goals for Australia.
Al Soma almost snatched an away-goals win for Syria in the dying moments, rattling the base of Ryan's left-hand post with a fine free-kick, but the Socceroos just held firm to break the hearts of the visitors.