Parentage clubs in a court case (9,4)
I believe the answer is:
paternity suit
'a court case' is the definition.
The definition suggests a singular noun which matches the answer.
'parentage clubs' is the wordplay.
I cannot quite see how this works, but
'clubs' could be 'suit' (clubs is an example of a card suit) and 'suit' is present in the answer.
The remaining letters 'paternity' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Another definition for paternity suit that I've seen is " A who's-the-daddy action".)