Due victory, it's secured by own goal (5)
I believe the answer is:
owing
'due' is the definition.
(similar in meaning)
'victory it's secured by own goal' is the wordplay.
'victory' becomes 'win' (I've seen this before).
'it's secured by' indicates putting letters inside (I've seen this in other clues).
'own goal' becomes 'OG' (football abbreviation).
'win' going within 'og' is 'OWING'.
(Other definitions for owing that I've seen before include "This debt has yet to be paid" , "Unsettled; on account" , "Outstanding as a debt" , "Still outstanding" , "Due to, like debt" .)