Surprise in a puzzle (5)
I believe the answer is:
amaze
'surprise' is the definition.
(I know that amaze is a type of surprise)
'a puzzle' is the wordplay.
'puzzle' becomes 'maze' (maze can mean a puzzling situation).
'a'+'maze'='AMAZE'
'in' acts as a link.
(Other definitions for amaze that I've seen before include "Stun" , "Greatly surprise, astound" , "Greatly surprise in a labyrinth" , "shock" , "Surprise greatly, astonish" .)