For almost 120 minutes of nail biting action, it looked as though a penalty shootout would be required to separate two teams who had been equally matched over two legs.
But, after 110 minutes, Australian stalwart Tim Cahill popped up with a 50th goal for his country to send the Socceroos through to the intercontinental play-off. Cahill's second goal of the game gave Australia a 2-1 victory and a 3-2 aggregate win.
In far better conditions than the two teams had encountered in the first leg in Malaysia -- a difficult pitch allied to humid weather -- many had written Syria off before a ball had been kicked in Sydney.
But any doubts as to whether the "Qasioun Eagles" were in with a genuine chance of continuing their World Cup journey were dispelled after just six minutes.
Mark Milligan's stray pass in midfield was pounced upon by Tamer Haj Mohamad, who drove at the heart of the Australia defense.
The midfielder, who plays for the Dhofar Club in Oman, spotted Omar Al Somah's run and threaded a through ball into his path.
Syria's star striker took two touches -- one to cushion the pass, the second a fortunate bobble -- before calmly drilling the ball high over Mathew Ryan in the Australian goal.
In truth, the goal was against the run of play. As they did in the first leg, Australia started the match with intent but without much of a cutting edge.
And if the sizable following of Syrian fans inside Sydney's Allianz Stadium had begun to dream of Russia, they were left deflated just seven minutes later.
Tom Rogic's pass down the line was curled brilliantly into the box first time by Matthew Leckie.
Lurking with intent at the far post, as he has done throughout his career, was the 37-year-old Cahill -- coming to Australia's rescue once again -- who headed the ball back across goal past the helpless Ibrahim Alma.
That goal injected a bit more confidence into the Australian team and there was now an assuredness and intent to their passing.
World Cup draw
Entering the second half, Alma became increasingly busy in the Syrian goal. First, he got down smartly to deny Cahill a second, before he could only watch on as Rogic curled an effort inches wide.
As the tension rose it looked inevitable that the game would be heading into extra time, only for a rash decision by midfielder Mahmoud Al Mawas to turned the match on its head.
A second yellow card for a late, reckless challenge handed the advantage to Australia at a time when Syria looked to be dealing comfortably with everything their opponents threw at them.
After the sending off it was a matter of when, not if, Australia would take the lead. Eventually that goal came and it was that man again Cahill who was in the right place at the right time.
Robbie Kruse chipped the ball back into the box after being found by substitute Aaron Mooy and Cahill leapt high above his marker to nod the ball past Alma's despairing dive.
Arguably Australia's greatest player, nobody has scored more for the Socceroos than Cahill.
Even so Syria were to have one last, agonizing chance to draw level through Al Somah.
Stepping up to a free kick 25 yards from goal, with a poise and posture almost identical to that of Cristiano Ronaldo, Al Somah's effort beat Ryan but crashed off the outside of the post.
The rattling of the woodwork signaled the end for Syria and their against all odds World Cup campaign.
Australia will now likely face either Panama or Honduras over two legs for a place at Russia 2018 next summer.
There will be 32 nations at the World Cup in 2018, with the draw for the tournament to take place inside the concert hall at Moscow's State Kremlin Palace on December 1.
The 2018 World Cup's first game will feature hosts Russia on June 14 in Moscow's Luzhniki Stadium.