Support the winner (8)
I believe the answer is:
champion
I believe this is a double definition.
'support' is the first definition.
(championing is a kind of supporting)
'the winner' is the second definition.
(thesaurus)
(Other definitions for champion that I've seen before include "Successful contender" , "Champ" , "Support - victor" , "Winner - advocate" , "Campaigner or winner" .)