South Korea booked their place at the World Cup in Qatar on Tuesday after Paulo Bento's side beat Syria 2-0 in Dubai to confirm their progress to a 10th consecutive finals.
Second-half goals from Kim Jin-su and Kwon Chang-hoon ensured the Koreans continue a run of successive qualifications that stretches back to Mexico in 1986 as they wrapped up a top-two finish in Group A of Asia's preliminaries.
The South Koreans join Iran in confirming their place at November's finals after Dragan Skocic's side claimed their ticket for Qatar on Thursday.
Only the top two finishers in each of Asia's two qualifying groups can claim guaranteed berths at the finals, while the third-placed nations will face off for the right to meet South American opposition in an intercontinental playoff.
Kim Jin-su put the Koreans in front eight minutes into the second half, the Jeonbuk Motors left back rising to meet Kim Tae-hwan's cross from the right and power his header home.
Kwon Chang-hoon made sure of the win 18 minutes from fulltime with a dipping left-footed strike from outside the area that bounced beyond goalkeeper Ibrahim Alma.
Lebanon and Iraq drew 1-1, further diminishing both of those nations' chances of finishing third in Group A.
Japan, meanwhile, closed in on the finals with a 2-0 victory over Group B leaders Saudi Arabia at Saitama Stadium that moves Hajime Moriyasu's side to within a point of the summit.
Takumi Minamino and Junya Ito were on target for the Samurai Blue as they handed Herve Renard's side a first defeat of the current round of preliminaries.
Winger Ito rolled the ball to Minamino and his attempt was powerful enough to prevent Mohammed Al Owais from keeping it out as Japan went in front in the 32nd minute.
Five minutes after the restart Ito went from provider to goalscorer with a stunning strike from the edge of the area, leaving Al Owais with no chance as the ball flew into the top corner.
Saudi Arabia's loss will give hope to third-placed Australia, who take on Oman in Muscat later on Tuesday.
Vietnam picked up their first win of the campaign as their 3-1 victory in Hanoi ended China's slim hopes of finishing third in Group B and claiming a playoff berth.
