Architect’s major centre developed on true area, briefly (5,5)

I believe the answer is:

joern utzon

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'architect's major centre developed' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'on true area briefly' is the wordplay.
I cannot really see how this works, but
'on' is present in the answer.
This explanation may well be incorrect...

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

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