Lift prize cup of the highest quality (3-6)
I believe the answer is:
top-drawer
'the highest quality' is the definition.
(I've seen this before)
'lift prize cup' is the wordplay.
'lift' says the letters should be written in reverse (I've seen 'lifted' mean this (going up in down clue)).
'prize' becomes 'reward' (a prize may be given as a reward).
'cup' becomes 'pot'.
'reward'+'pot'='rewardpot'
'rewardpot' written backwards gives 'TOP-DRAWER'.
'of' acts as a link.
(Other definitions for top-drawer that I've seen before include "Excellent" , "of high social standing" , "Of the highest standing" , "Perfect" .)