Foreign heavyweight who often won on points (5)
I believe the answer is:
alien
'foreign' is the definition.
(similar in meaning)
'heavyweight who often won on points' is the wordplay.
I cannot really understand how this works, but
'heavyweight' could be 'ali' (I've seen this before) and 'ali' is found within the answer.
'points' could be 'en' (two compass points) and 'en' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for alien that I've seen before include "Outlandish" , "ET" , "Stranger" , "Clanger?" , "exciting film based in space" .)