State broadcast headline act (4,5)

I believe the answer is:

main event

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'headline act' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'state broadcast' is the wordplay.
'state' becomes 'maine' (US state).
'broadcast' becomes 'vent' (I've seen this before).
'maine'+'vent'='MAIN EVENT'

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I've seen this clue in The Independent.

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