Shot over angle's defended in exciting climax (5,6)
I believe the answer is:
photo finish
'exciting climax' is the definition.
The definition suggests a singular noun which matches the answer.
'shot over angle's defended in' is the wordplay.
I cannot quite see how this works, but
'shot' could be 'photo' (I've seen this before) and 'photo' is found in the answer.
'in' is within the answer.
'angle' could be 'fish' (synonyms) and 'fish' is found within the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for photo finish that I've seen before include "Close ending to a race" , "Virtual dead heat in a horse race" .)