Hits Stosur's return to Hungarian No.1. Two points! (7)
I believe the answer is:
smashes
'hits' is the definition.
(I know this)
'stosur's return to hungarian no 1 two points' is the wordplay.
'stosur' becomes 'sams' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'return' says the letters should be written in reverse.
'to hungarian no s' becomes 'h' (sst letter of 'hungarian').
'two points' becomes 'ES' (two compass points).
'sams' written backwards gives 'smas'.
'smas'+'h'+'es'='SMASHES'
Can you help me to learn more?
(Another definition for smashes that I've seen is " Accidents".)