Lieutenant suffering setback in match for championship (5)
I believe the answer is:
title
'championship' is the definition.
('title' can be a synonym of 'championship')
'lieutenant suffering setback in match' is the wordplay.
'lieutenant' becomes 'lt'.
'suffering setback' says the letters should be written in reverse.
'in' means one lot of letters goes inside another.
'match' becomes 'tie' (I've seen this before).
'lt' back-to-front is 'tl'.
'tl' put into 'tie' is 'TITLE'.
'for' is the link.
(Other definitions for title that I've seen before include "Right to possession" , "Rank < deed" , "One published" , "Appellation signifying status or function" , "'The name of a book, say (5)'" .)