It was a second 6-0 win in as many games for the Olyroos, after they defeated Cambodia by the same scoreline in their first Group H match on Friday.
Western Sydney Wanderers forward Abraham Majok scored the opening two goals, before Melbourne Victory defender Thomas Deng made it 3-0 just before half-time.
Wanderers defender Tass Mourdoukoutas headed home from a corner after half-time to give Australia a four-goal lead, before 20-year-old Pierce Waring scored a late brace to secure the 6-0 victory.
In the other pool match, South Korea defeated Cambodia 6-1 to sit top of the group on goal difference.
The results set up a Tuesday night showdown between Australia's U-23s and the South Koreans for top spot in the group.
Only the winners of the group are assured of progression to January's AFC U-23 Championship in Thailand - the final 16-team qualifying tournament for the Olympics from which only three teams will advance to Tokyo 2020.
The nation that tops the group automatically qualifies for the 2020 AFC U-23 Championship, along with the best four second-place teams.
The fifth-best second-placed team from the 11 groups will also qualify should Thailand – who have qualified automatically for the tournament as hosts – finish as either Group K winners or runners-up.
