Upper-class boozer holding raffle (3-6)
I believe the answer is:
top-drawer
'upper-class' is the definition.
(top drawer can informally mean upper-class)
'boozer holding raffle' is the wordplay.
'boozer' becomes 'toper' (both can mean someone who drinks a lot).
'holding' is an insertion indicator.
'raffle' becomes 'draw' (a prize draw).
'toper' placed around 'draw' is 'TOP-DRAWER'.
(Other definitions for top-drawer that I've seen before include "of high social standing" , "Of the highest standing" , "Perfect" , "Excellent" .)