Author served up very fine port (7)
I believe the answer is:
nabokov
'author' is the definition.
(I've seen this before)
'up very fine port' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'very' becomes 'v' (abbreviation).
'fine' becomes 'ok' (synonyms).
'port' becomes 'oban' (Oban is a Scottish port).
'v'+'ok'+'oban'='vokoban'
'vokoban' reversed gives 'NABOKOV'.
'served' acts as a link.
(Other definitions for nabokov that I've seen before include "Lolita writer" , "Author of ''Lolita'' in book van" , "Vladimir --, author" , "Wrote Lolita and Pale Fire" , "Russian author" .)