Heading for victory, were poor moves to create defeat? (9)
I believe the answer is:
overpower
'defeat?' is the definition.
(overpowering is a kind of defeating)
'heading for victory were poor moves' is the wordplay.
'heading for' says to take the initial letters.
'moves' indicates anagramming the letters.
The first letter of 'victory' is 'v'.
'v'+'were'+'poor'='vwerepoor'
'vwerepoor' anagrammed gives 'OVERPOWER'.
'to create' acts as a link.
(Other definitions for overpower that I've seen before include "Get the better of" , "Defeat with superior strength" , "Conquer" , "Subdue, vanquish" , "Subdue by greater strength or numbers" .)