Only Hitchcock film to win Best Picture (7)
I believe the answer is:
rebecca
'only hitchcock film to win best picture' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rebecca that I've seen before include "also Isaac" , "she loved Ivanhoe" , "Literary heroine" , "Isaac's wife" , "One of the four matriarchs of the Jewish people (anglicised)" .)