Fix a Latvian city (4)
I believe the answer is:
riga
'latvian city' is the definition.
(I've seen this in another clue)
'fix a' is the wordplay.
'fix' becomes 'rig' (rig can mean to fix or manipulate).
'rig'+'a'='RIGA'
(Other definitions for riga that I've seen before include "port in Latvia" , "A rig in Latvia" , "Baltic capital city" , "trading centre in Latvia" , "European capital" .)