Watch the first man to take over - it will surprise you (9)
I believe the answer is:
eyeopener
'man to take over it will surprise you' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.
'watch the first' is the wordplay.
'watch' becomes 'eye' (eye can mean to watch or look at).
'the first' becomes 'opener' (I've seen this before).
'eye'+'opener'='EYEOPENER'
Can you help me to learn more?
(Other definitions for eyeopener that I've seen before include "For Uncle Sam, perhaps hair of the dog" , "revelation" , "piece of information that's surprising" .)