SEOUL, South Korea — When Australia narrowly defeated South Korea in the final of the 2015 Asian Cup, the prospect that World Cup qualifying for these two continental soccer heavyweights would depend on war-torn Syria was barely even a consideration.

In the third round, with just the top two teams in each group qualifying automatically for Russia, South Korea scraped through in second spot in Group A. The Taeguk Warriors would have dropped to third if Syria had beaten already-qualified Iran rather than being held to a 2-2 draw.

Australia missed out on direct qualification by a fraction in Group B, when Saudi Arabia edged already-qualified Japan 1-0 in the last game of the round and edged the Socceroos for second spot because of a superior goal difference.

Now Australia faces Syria in a two-match October playoff for the right to enter a November showdown with the fourth-place team from CONCAFAF, the Central and North American region. The winner of the intercontinental playoff will earn a spot at Russia 2018.

“I am very proud of my players,” Syria coach Ayman Hakeem said. “We still have a chance of going to the World Cup. It is too early to talk about Australia, but we know it will be a tough game.”

Syria’s achievement is all the more impressive as the team has been unable to play games at home because of the ongoing conflict in the country. Home games have instead been at a relatively empty stadium in Malaysia. Some of Syria’s best players, including Firas Al Khatib and Omar Al Soma, missed much of the campaign after expressing support for the opposition to the ruling regime in the war-torn country.

Al Soma, who plays for a Saudi club, returned for the penultimate game with Qatar and then scored the all-important second goal against Iran deep into injury-time in Tehran.

While Syrians were euphoric at advancing to a playoff, the Australian players were already visibly shaken immediately after a 2-1 win over Thailand left their World Cup hopes hinging on Japan avoiding defeat in Jeddah.

The Asian champions had a frustrating evening in Melbourne, where their lack of composure and finish turned into panic as they chased the big winning margin they needed to put pressure on Saudi Arabia. Japan won the group with 20 points, one clear of the Saudis and the Australians, who only had one loss in the qualifying round — away to Japan last week.

Socceroos coach Ange Postecoglou has subsequently come in for increasing criticism, with the likes of former Manchester United and Australia goalkeeper Mark Bosnich questioning if the coach was the right person for the job.

“I won’t waste my time responding to criticism,” Postecoglou said. “I won’t be pushed into the shadows of Australian football history like others. I have survived worse than this.”

South Korea has made qualification a habit since 1986, and sneaked into a ninth successive World Cup. Only five teams — Brazil, Argentina, Spain, Germany and Italy — have longer consecutive runs on the global stage.

The South Koreans finished second with 15 points, seven behind Iran. Syria collected 13 points, edging out Uzbekistan on goal difference.

Uzbekistan would have qualified with a win over South Korea in in Tashkent. The Koreans dominated a 0-0 draw and had a number of chances to win the game. The South Koreans failed, however, to get the goal that would have secured a World Cup spot without having to rely on Iran picking up a point against Syria.

“It’s a pity that we couldn’t win here, but I want to thank all fans here and South Korea that we’re able to qualify for the World Cup with a draw,” coach Shin Tae-yong said.

It has been a troubled campaign for the South Koreans, who picked up just one victory in their last five qualifiers. A June defeat at last-place Qatar cost Uli Stielike his job as head coach with two games remaining.

Shin will extend his tenure as far as next summer when the 2002 semifinalists will try to bounce back from a dismal showing at the 2014 World Cup.

“We will prepare for the World Cup thoroughly,” he said. “I’m a man who likes to play attacking football. People will find out about South Korea’s true football power at the World Cup.”