South Korea booked their place at a ninth straight World Cup finals on Tuesday evening as a 0-0 draw with Uzbekistan was enough for Shin Tae-yong and his team to book their ticket for Russia while Saudi Arabia's 1-0 win over Japan condemned Australia to a place in the playoffs.
Fahad Al Muwallad's thunderbolt of a strike ensured the Saudis will go to the World Cup for the first time since 2006, joining Japan, South Korea and Iran as Asia's representatives at next year's tournament.
Australia, meanwhile, will take on Syria in the playoffs next month for the right to meet the fourth-placed team in CONCACAF and become a fifth representative of the Asian Football Confederation in the draw when it is made in Moscow in December.
However, there was heartbreak for Uzbekistan as a late goal from Omar Al Soma in Tehran saw Syria move into third place in the group as Aymen Hakeem's side sealed a 2-2 draw with already-qualified Iran on a dramatic final night of Asia's qualifying campaign.
South Korea ensured they would finish in second place in Group A behind the Iranians and two points clear of Syria as the nation continued their remarkable run of consecutive appearances at the World Cup.
Lee Keun-ho, Son Heung-min and Lee Dong-gook all hit the woodwork for the Koreans at Pakhtakor Stadium, with the home side not doing enough to keep their hopes of a first-ever World Cup appearance alive.
Those dreams were dashed in Tehran when Al Soma struck deep into injury time to slot the ball between the legs of Alireza Beiranvand and give the Syrians a point that took them into third place on goal difference.
Syria and Australia, the teams in third place in each group, will face off against each other in October, with the winners entering into an intercontinental playoff against the fourth-placed team in CONCACAF in November.
Syria booked their place in the elimination phase after an impressive fight back late in the game.
Tamer Haj Mohamed scored for the Syrians -- the first goal Iran have conceded in more than 12 qualifying matches -- from close range after 13 minutes before a double from Sardar Azmoun looked set to give the Iranians all three points.
But Al Soma, who only returned to the team last month after a lengthy self-imposed exile, slipped the ball home to send the Syrians into raptures.
Because of the ongoing civil war in Syria, the national team has not played any qualifiers in their home country. For the final round, they played in Malaysia, while in the previous round they played in Oman.
Syria was ranked 151st in the world by FIFA in January 2015, the rankings used to seed the first AFC qualifying draw. For the final round's seedings in April 2016, they were ranked 110th, the second-lowest of the 12 teams in contention. Syria are up to 80th in the latest rankings released Aug. 10.
Hakeem and his players will take on the Australians after Ange Postecoglou's team were pushed down into third place in Group B as a result of Saudi Arabia's win over the Japanese.
After a tense first half, the pace and penetration of substitute Al Muwallad caused the Japanese defence numerous problems and it came as no surprise when he gave the home side the lead in the 63rd minute, smashing the ball high into the net from eight yards out.
The goal sent the majority of the more than 62,000 fans inside the King Abdullah Sports City in Jeddah in raptures and the Saudis managed to hold in stifling conditions to secure the country's fifth appearance at the World Cup finals.
Saudi Arabia's win was a bitter blow for Australia who will go into the playoffs despite Ange Postecoglou's side notching up a 2-1 win over Thailand in Melbourne.
Tomi Juric gave the Australians the lead in the 69th minute only for Pokklaw Anan to level with eight minutes go. But Mathew Leckie claimed the goal four minutes from time that kept Australia's hopes of an automatic berth alive for a few more hours.
The United Arab Emirates' slim hopes were extinguished when Iraq's Aymen Hussein scored the only goal of their meeting in Amman in Jordan while China finished with a flourish as Marcello Lippi's side defeated Qatar 2-1.
Xiao and Wu Lei scored after Akram Afiff had given the 2022 World Cup hosts the lead, as the Chinese narrowly missed out on keeping their chances of a second World Cup appearance alive.