Northern European allowed to finish first (4)
I believe the answer is:
lett
'northern european' is the definition.
(I've seen this in another clue)
'allowed to finish first' is the wordplay.
'allowed to' becomes 'let' (to let something happen is to allow it).
'finish' indicates one should take the final letters.
The last letter of 'first' is 't'.
'let'+'t'='LETT'
(Other definitions for lett that I've seen before include "northerner" , "Balt" , "East European" , "Native of Latvia" , "Baltic citizen" .)