Three points go to my opponent (5)
I believe the answer is:
enemy
'opponent' is the definition.
(I know that enemy is a type of opponent)
'three points go to my' is the wordplay.
'three points' becomes 'ene' (I've seen this in other clues).
'go to' means one lot of letters go next to another.
'ene'+'my'='ENEMY'
(Other definitions for enemy that I've seen before include "Hostile person, foe" , "one in opposition" , "Opposing force" , "is against us" , "Antagonist" .)