Champion left after drink (7)
I believe the answer is:
support
'champion' is the definition.
(I've seen this before)
'left after drink' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'after' means one lot of letters go next to another.
'drink' becomes 'sup' (to sup is to drink).
'port' after 'sup' is 'SUPPORT'.
(Other definitions for support that I've seen before include "Cheer" , "Maintain, back" , "used to give strength?" , "Give assistance to" , "Stay" .)