Owner to support rioter, strangely (10)
I believe the answer is:
proprietor
'owner' is the definition.
(I know that owner is a class)
'support rioter strangely' is the wordplay.
'support' becomes 'prop' (prop up can mean to support).
'strangely' indicates an anagram.
'rioter' is an anagram of 'rietor'.
'prop'+'rietor'='PROPRIETOR'
'to' is the link.
(Other definitions for proprietor that I've seen before include "Business owner" , "Landlord" .)