Goals from Lukas Podolski and Miroslav Klose inside half an hour set the three-time world champions on their way before Tim Cahill was dismissed for a late challenge on Bastian Schweinsteiger.
Further efforts in the second period from Thomas Muller and Cacau ensured Germany topped their group in fine style.
Germany started the game in emphatic fashion and they took an eighth minute lead through Podolski.
- Group D Fixtures However, things could have been much different if Phiippe Lahm hadn't blocked Richard Garcia's goal-bound strike in the opening moments.
Thomas Muller beat the offside trap and his pull-back evaded Klose, but Podolski was there to slam home beyond Mark Schwarzer in the Australia net.
The Germans almost extended their lead when a quick free-kick was threaded to Muller on the right and, as he fired a low cross into the area, the despairing dives of Klose and Podolski proved unsuccessful as the ball tantalisingly passed them.
Moments later, Klose was guilty of missing an absolute sitter as Podolski found him from the left.
But the Bayern Munich man sliced high-and-wide with just Schwarzer to beat from ten-yards.
He was soon to make amends as he beat the onrushing Schwarzer to Lahm's pin-point right-wing cross to double the lead.
Five minutes later, the mercurial Mesut Ozil skipped through and clipped a delicate effort over a beleaguered Schwarzer, but the effort was cleared when a goal seemed certain.
Podolski and Ozil combined again as the diminutive play-maker was played through on goal. He rounded the Socceroos stopper, but a heavy touch ended the opportunity.
Disaster struck in the 56th minute as the Socceroos were reduced to ten-men.
Midfield chief Cahill was dismissed by referee Marco Rodriguez for a lunge on Schweinsteiger and the floodgates were soon to open.
Muller finished off a flowing move via the far post and, just a minute after his introduction, Brazil-born forward Cacau slid home his first international goal Ozil's square ball.
Germany continued to press as Joachim Low freshened things up with the introduction of Mario Gomez and Marko Marin, but despite further prolonged spells of domination, there were no further goals.
Source: DSG
