A lost duet unexpectedly survived (9)

I believe the answer is:

outlasted

'survived' is the definition.
('outlast' can be a synonym of 'survive')

'a lost duet unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'a'+'lost'+'duet'='alostduet'
'alostduet' anagrammed gives 'OUTLASTED'.

(Another definition for outlasted that I've seen is " Survived longer than".)

I've seen this clue in The Independent.

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