Famous painting in oils a man vandalised (4,4)
I believe the answer is:
mona lisa
'famous painting' is the definition.
(the Mona Lisa is a painting by Leonardo da Vinci)
'oils a man vandalised' is the wordplay.
'vandalised' indicates an anagram.
'oils'+'a'+'man'='oilsaman'
'oilsaman' with letters rearranged gives 'MONA LISA'.
'in' is the link.
(Other definitions for mona lisa that I've seen before include "depicted, in the Louvre" , "Da Vinci painting" , "Louvre painting" , "Fertiliser from seabirds" , "Picture" .)