A shot sunk in a single stroke (4,2,3)
I believe the answer is:
hole in one
'a single stroke' is the definition.
The definition suggests a singular noun which matches the answer.
'a shot sunk in' is the wordplay.
I cannot really see how this works, but
'a' could be 'one' and 'one' is found within the answer.
'in' is found in the answer.
The remaining letters 'hole' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for hole in one that I've seen before include "The best possible shot by a golfer" , "Golfing feat" , "Singular achievement by golfer - literally" , "Singular score in golf" .)