To contradict wins, always (7)
I believe the answer is:
gainsay
'to contradict' is the definition.
(thesaurus)
'wins always' is the wordplay.
'wins' becomes 'gains' ('gain' can be a synonym of 'win').
'always' becomes 'ay'.
'gains'+'ay'='GAINSAY'
(Other definitions for gainsay that I've seen before include "Speak against" , "Challenge, dispute" , "Contradict, deny, dispute" .)