After shaky displays in friendly defeats by Russia and Brazil, coach Morten Olsen will be pleased with his goalkeeper and defence for keeping a clean sheet while his centre-backs even pitched in with the goals for good measure.
Liverpool's Daniel Agger opened the scoring, converting a first-half penalty after being felled in the box while chasing Christian Eriksen's sublime pass.
Andreas Bjelland, Agger's partner at centre back, scored midway through the second half to put Denmark two up as the Australian defence failed to deal with a corner.
Bjelland was one of three players from newly-crowned Danish champions FC Nordsjaelland to take the field, along with Jores Okore and Tobias Mikkelsen.
All came on as second-half substitutes.
The Australians did threaten on occasion, but Stephan Andersen, first-choice goalkeeper since Thomas Sorensen suffered a back injury against Brazil and withdrew from the squad, was up to the task.
For Denmark, the result will restore some of the self-confidence dented by recent friendly losses, even if the level of opposition offered by Australia fell far short of what the Danes can expect in Poland and Ukraine.
Denmark open their group B campaign against Netherlands in Kharkiv on June 9, before facing Portugal and Germany in their bid to reach the knockout stages.
