Wrestler returned inside box-like zone (5)
I believe the answer is:
ozeki
'wrestler' is the definition.
(sumo wrestling term)
'returned inside box-like zone' is the wordplay.
'returned' says the letters should be written in reverse.
'inside' indicates the answer is hidden within the clue.
'ikezo' is hidden within 'box like zone'.
'ikezo' back-to-front is 'OZEKI'.
(Other definitions for ozeki that I've seen before include "Sports champion" , "wrestling champ" .)