Japan qualified for a seventh successive World Cup after beating Australia 2-0 in Sydney and ending the Socceroos' chances of automatic qualification on Thursday.
The result also qualified Saudi Arabia from Asia Group B.
Japan was on top of the group with 21 points, two ahead of Saudi Arabia before it faced China later Thursday.
Australia remained in qualifying contention in third place. It faced a playoff against the third-place team from Group A, currently the United Arab Emirates, and a possible final game against South American opposition, according to The Associated Press.
The two late goals from substitute Kaoru Mitoma ended an entertaining game during which Japan had been wasteful. Takumi Minamino came close on five occasions.
Australia, however, thought it took the lead after 26 minutes when Gianni Stensness headed home a corner only for the referee to rule Trent Sainsbury fouled goalkeeper Shuichi Gonda.
Almost immediately, Minamino, who had four attempts on goal in the first half alone, almost gave Japan the lead, shooting just wide inside a crowded area.
Three minutes later, he headed against the inside of an Australia goal-post and the ball bounced into the arms of goalkeeper Matthew Ryan much to the relief of the home fans. Near halftime, Minamino hit the woodwork again, shooting against the crossbar after a dangerous run and pass from Yuto Nagatomo.
Australia started strong after the restart, but with 10 minutes remaining a Minamino shot from close range was cleared off the line by Sainsbury.
With a minute remaining, Japan finally broke the deadlock. Mitomo replaced Minamino five minutes earlier and slotted home after a pull back from Miki Yamane.
Deep inside stoppage time, Mitomo’s low shot bobbled under Ryan and sealed the vital win.
On Tuesday, Japan hosts Vietnam, bottom of the group with just one win, while Australia travels to Jeddah to take on Saudi Arabia.
