Aussie at odds with this region? (4)

I believe the answer is:

asia

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'this region?' is the definition.
(I have seen 'populous region' mean 'asia' so perhaps 'region' could also mean 'asia')

I don't understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for asia that I've seen before include "Huge landmass" , "Populous continent" , "Continental land mass" , "Part of the world" , "Stretch of land" .)

I've seen this clue in the Sydney Morning Herald.

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