Neither Thailand nor Iraq could do the Socceroos any favours on Tuesday night as Australia's win over United Arab Emirates failed to make inroads on Group B leaders Saudi Arabia and Japan.
The Green Falcons and the Samurai Blue reinstated their three-point lead over Australia in Group B of Asia's World Cup qualifying after Jackson Irvine and Mathew Leckie's goals had seen the Socceroos past the UAE in Sydney.
Japan crushed Thailand 4-0 in Saitama with Leicester City's Shinji Okazaki setting up Borussia Dortmund's Shinji Kagawa for the opener and then scoring the second himself.
Gent forward Yuya Kubo and Southampton defender Maya Yoshida completed the scoring in the second half as Japan moved ahead of the Saudis on goal difference.
Saudi Arabia sit second following a 1-0 win over Iraq in Jeddah with Yahya Al Shehri of Al Nassr scoring the winner seven minutes into the second half.
Australia host Saudi Arabia in their next World Cup qualifier in June in a match the Socceroos almost certainly must win to earn an automatic qualifying berth at Russia 2018.
MORE: Saudi Arabia's Yasser Al Shahrani: "I believe we will be able to qualify for the next World Cup" | World Cup 2018 Qualifier: Thailand 0-3 Saudi Arabia - Saudi Arabia hand a thrashing to Thai contingent
The Socceroos also visit Japan in August and host Thailand in their final Group B fixtures in September.