Defend winning wrestling move (6)
I believe the answer is:
uphold
'defend' is the definition.
(I know that uphold is a kind of defend)
'winning wrestling move' is the wordplay.
'winning' becomes 'up' (eg being up at half time in football).
'wrestling move' becomes 'hold' (I've seen this in another clue).
'up'+'hold'='UPHOLD'
(Other definitions for uphold that I've seen before include "'Support, the law say (6)'" , "Support a decision or belief" , "Sustain and endorse" , "Champion" , "Confirm or support, say a verdict" .)