Lightweight's hit below the belt, switching hands once? (7)
I believe the answer is:
lowbrow
'lightweight's' is the definition.
(both can mean uncultured or unsophisticated)
'below the belt switching hands once?' is the wordplay.
'below the belt' becomes 'low' (below the belt can mean morally low).
'switching hands once?' becomes 'brow' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'low'+'brow'='LOWBROW'
'hit' is the link.
I am not very happy about this link. It may be part of another bit of the clue.
(Other definitions for lowbrow that I've seen before include "One preferring pop to classical" , "(Person) uninterested in intellectual pursuits" , "Unsophisticated" , "Mass-market" , "Hard mass in wood, shore bird" .)