Sydney - Syria coach Ayman al-Hakim said Mahmoud al-Mawas's extra-time red card was the turning point as his war-torn team's fairytale World Cup bid ended in the Asian play-offs on Tuesday.
Al-Hakim said the rank outsiders would have survived until penalties against Australia if al-Mawas hadn't been sent off for a second bookable offence early in the first extra period.
Syria's players were left inconsolable after Tim Cahill's 109th-minute winner sealed it 2-1 on the night and 3-2 on aggregate for Australia, who now go into an intercontinental play-off.
Omar al-Soma also thundered a free kick against the post in the dying seconds as the Qasioun Eagles, who have never reached the World Cup, came within inches of a shock play-off victory.
"The players followed instructions very, very well. But the Australian goal happened because of the pressure of the Socceroos," al-Hakim said.
"The first goal was a small mistake, not a major mistake, and the second goal was because we had 10 players," he added.
"We studied the Socceroos very well and I think if we had stayed at 11 players and hadn't had that red card and hit the (post) at the end (it would have been different).
"But I am very proud of my boys with what they have achieved so far, and that's going to be continuing moving forward as well."
Al-Soma had opened the scoring for Syria in the sixth minute before Cahill headed Australia level seven minutes later in an entertaining first half.
Syria kept the Asian champions at bay in the second half but in extra time, they were left with a mountain to climb when al-Mawas lunged at Robbie Kruse and received his second yellow card.
Syria's resistance finally cracked when Cahill nodded his second goal on 109 minutes to take Australia into a final play-off with the CONCACAF federation's fourth-placed team, currently Panama.
"I apologise on behalf on all my fellow players to the Syrian people," forward Firas al-Khatib told beIN Sports.
"We were hoping to provide a smile and joy to Syrians everywhere. Our disappointment is very big."
Syria, who play their 'home' fixtures in Malaysia to avoid the conflict in their country, had defied the odds to finish third in their final qualifying group behind Iran and South Korea.
Al-Hakim said they missed their chance by not beating Australia in last week's first leg in Malacca, where they had several chances but needed a debatable late penalty to draw 1-1.
"Our true loss was that we failed to win the previous match," he said. "The Australian team is experienced... we were without many important players and this certainly had an impact."