Put back in control over unfinished match (8)
I believe the answer is:
reinvest
'put back in' is the definition.
'control over unfinished match' is the wordplay.
'control' becomes 'rein' (rein is a kind of control**).
'over' is a charade indicator (letters next to each other).
'unfinished' means to remove the last letter.
'match' becomes 'vesta' (type of historical wooden match).
'vesta' with its final letter taken off is 'vest'.
'rein'+'vest'='REINVEST'
(Other definitions for reinvest that I've seen before include "Seek further profits" , "Lay out more money" , "get back into market" , "Put back money into the same business" , "mount further siege" .)