Challenged champion's delay about the final (8)
I believe the answer is:
defender
'challenged champion's' is the definition.
'defender' can be an answer for 'champion's' (I've seen this before). I'm not sure about the 'challenged' bit.
'delay about the final' is the wordplay.
I cannot really understand how this works, but
'final' could be 'end' (synonyms) and 'end' is located in the answer.
'delay' could be 'defer' (deferring is a kind of delaying) and 'defer' is located in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for defender that I've seen before include "Centre half, perhaps" , "One who takes up the cause of another" , "Back" , "Guardian" , "One who protects others" .)