Hit yourself (6,3)
I believe the answer is:
number one
This clue is a double definition.
'hit' is the first definition.
(I've seen this before)
'yourself' is the second definition.
(I've seen this before)
(Other definitions for number one that I've seen before include "Musical success" , "arch" , "Informally the self, numerically speaking" , "top of the pops" , "Informally and numerically, oneself" .)