While it was not the most convincing of their three appearances at the tournament in Darwin, it was enough to assure the Australians of a top-two finish at the end of qualification.
The home side now finds itself just one win away from the gold medal match, most likely against England, in what would be a dream finale to a quality tournament.
Australia will meet third-placed Japan in Saturday?s semi-final, while top-qualifiers England will play against fourth-placed Korea. Both winners will then progress to Sunday?s Oceania Paralympic Championship gold medal decider.
If Australia is to fight on, coach Paul Brown admits his men have to be more clinical in front of goal. Despite a glut of possession in both halves, the barrage of Australian shots repeatedly struggled to really test the Japanese goal keeper.
Their opening goal came care of an own-goal from Japanese defender Kawabe Keisuke in the eighth minute, while Thomas Goodman (21st minute) and Beau Menzies (24th minute) managed to buck the trend of missed opportunities and put their names on the score sheet.
Menzies? effort was particularly impressive, a long range strike that left Japanese keeper Yatsuda Kenji with little hope.
?The finishing in front of goal just wasn?t clean enough,? Brown said.
?The lead-up play was quite good but the shooting was just a bit off. Japan defended well and was able to get a toe to a lot of balls, which made things harder for us.?
But generally, the Australian coach was content with his side?s performance although he did admit that he will be asking them to step up a gear now that the Championships are do-or-die.
?Now that we?re getting to the crunch part of the tournament, we need to start lifting our intensity,? Brown said.
?The guys have remained nice and relaxed up here during the tournament, but now is the time we need to start playing a lot sharper. There are no second chances from here on in.?