Presumably no pointless contest! (6,5)
I believe the answer is:
needle match
'presumably no' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'pointless contest' is the wordplay.
'pointless' becomes 'needle' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'contest' becomes 'match' (match is a kind of contest).
'needle'+'match'='NEEDLE MATCH'
Can you help me to learn more?
(Other definitions for needle match that I've seen before include "local derby, perhaps" , "grudge game" .)