Drink after drink for champion (7)
I believe the answer is:
support
'champion' is the definition.
(I've seen this before)
'drink after drink' is the wordplay.
'drink' becomes 'sup' (I've seen this before).
'after' says to put letters next to each other.
'drink' becomes 'port' (port is a kind of drink).
'sup'+'port'='SUPPORT'
'for' is the link.
(Other definitions for support that I've seen before include "Bear; assistance" , "Cheer" , "comfort" , "Give assistance to" , "Bolster or back up" .)