Work left Tunis, sadly - he will take advantage (11)

I believe the answer is:

opportunist

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'he will take advantage' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'work left tunis sadly' is the wordplay.
'work' becomes 'op' (common abbreviation for 'opus').
'left' becomes 'port' (left side of a ship - opposite of starboard).
'sadly' indicates an anagram.
'tunis' anagrammed gives 'unist'.
'op'+'port'+'unist'='OPPORTUNIST'

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(Other definitions for opportunist that I've seen before include "One making most of" , "One taking advantage of changing circumstances" , "Person without fixed principles" , "Chancer" .)

I've seen this clue in The Daily Express.

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