In another clear statement the Socceroos are getting more confident in Ange Postecoglou's style, they dominated Oman in a devastating first half to book their quarter-final berth with a game to spare.
Matt McKay, Robbie Kruse and Mark Milligan all found the net prior to the interval and a goal for substitute Tomi Juric midway through the second period completed the rout.
Remarkably, the eight goals the Socceroos have netted in the first two matches have been scored by eight different players.
The result means Australia only need a draw from their final group game with South Korea on Saturday night to top the group.
Postecoglou made three changes from the tournament opener, bringing in Milligan, McKay and Jason Davidson for Mile Jedinak, James Troisi and Aziz Behich.
And Australia again made a slow start, with only a superb full-length save by Mat Ryan keeping out Raed Saleh's rasping early drive.
It took almost 20 minutes for the hosts to find their feet, but Oman had no answer once Australia clicked into gear.
First McKay turned the ball in from close range after Trent Sainsbury had risen highest to head Massimo Luongo's corner towards goal.
On the half hour it was 2-0 as Kruse started and finished a brilliant move which had the crowd of 50,276 on their feet.
Luongo was again involved, sending Kruse through with a classy lofted pass over the top with the outside of his right foot, and the Bayer Leverkusen man finished low and hard under Ali Al Habsi.
By now the Socceroos were flying and only the width of the post denied Kruse a second before Milligan made it three in bizarre circumstances during first-half stoppage time.
A flowing move ended with Milligan having an easy tap-in at the far post, but Japanese referee Ryuji Sato surprised everyone by blowing for a penalty after Tim Cahill was fouled in the build-up.
It mattered little as Milligan buried his spot-kick to have the result put to bed by half-time.
Even with Cahill and Luongo substituted early in the second half the hosts kept up the intensity throughout and added a fourth goal their industry merited.
Juric got himself on the scoresheet 20 minutes from time when he slid in at the far post after wonderful work by Mathew Leckie down the left.
Only the sharp reflexes of Al Habsi prevented both Milligan and Juric from adding further gloss to the score late on but it mattered little on a memorable night for the Socceroos.
