Pal spots rivals (9)
I believe the answer is:
opposites
'rivals' is the definition.
The answer and definition can be both people as well as being plural nouns.
Maybe you can see an association between them that I don't see?
'pal spots' is the wordplay.
'pal' becomes 'oppo' (I can't justify this - if you can you should give a lot more credence to this answer).
'spots' becomes 'sites' (spot can mean a site or location).
'oppo'+'sites'='OPPOSITES'
Can you help me to learn more?
(Other definitions for opposites that I've seen before include "hot and cold?" , "said to be attractive" , "counters" , "What proverbially attract" , "such as the Poles?" .)