Support from Victor accompanied by expression of pain (5)
I believe the answer is:
vouch
'support' is the definition.
(thesaurus)
'victor accompanied by expression of pain' is the wordplay.
'victor' becomes 'V' (phonetic alphabet: alpha, bravo, charlie etc.).
'accompanied by' is a charade indicator (letters next to each other).
'expression of pain' becomes 'ouch' (I've seen this before).
'v'+'ouch'='VOUCH'
'from' acts as a link.
(Other definitions for vouch that I've seen before include "Be surety (for)" , "Testify" , "Declare support" , "warrant" , "Give personal assurance; guarantee" .)