Unique contest taking off (9)
I believe the answer is:
matchless
'unique' is the definition.
(I've seen this before)
'contest taking off' is the wordplay.
'contest' becomes 'match' (match is a kind of contest).
'taking off' becomes 'less' (less can mean take away or subtracting).
'match'+'less'='MATCHLESS'
(Other definitions for matchless that I've seen before include "reason for rubbing sticks together?" , "beyond compare" , "Unbeatable" , "Second to none" , "team without a fixture" .)