Leicester City defender Harry Souttar's fourth-minute header set the tone in Melbourne as the Socceroos enjoyed a perfect start in their bid to make the expanded 48-team tournament in the United States, Canada and Mexico.
Mitchell Duke added two more and Brandon Borrello was also on target as the hosts raced 4-0 clear by the break, before Maclaren's second-half bonanza, all well-taken tap-ins.
"Seven goals, but it could have been more, for me too, but three points and we move on. I'm not even sure (goalkeeper) Maty (Ryan) had a save to make so proud of the team, but we obviously know the next games are going to be harder," said Maclaren.
Australia are also pitted in Group I with Palestine and Lebanon, who meet in Sharjah later. A record eight direct spots and one intercontinental playoff berth are at stake for Asian Football Confederation sides, from nine groups of four.
Japan and South Korea play later Thursday, against Myanmar and Singapore respectively. Japan are targeting an eighth straight World Cup and the Koreans an 11th. Both sides made the last 16 at Qatar 2022, as did Australia.
Elsewhere, Saudi Arabia, who upset eventual champions Argentina in Doha, face Pakistan, perennial underperformers China meet Thailand and heavyweights Iran take on Hong Kong.
The top two from each group go through to the final qualifying round, with Graham Arnold's Socceroos aiming to be among them as they eye a sixth consecutive World Cup. Ranked 27 in the world to Bangladesh's 183, they were always on top at AAMI Park, dominating possession against a team that created few opportunities.
Australia needed just four minutes to open their account, with towering Scottish-born Souttar rising unmarked to head home Graig Goodwin's floating free kick
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