Well-matched piece of pure quality (5)
I believe the answer is:
equal
'well-matched' is the definition.
'piece of pure quality' is the wordplay.
'piece of' indicates the answer is hidden within the clue.
'EQUAL' is hidden in the letters of 'pure quality'.
(Other definitions for equal that I've seen before include "Keep pace with - peer" , "What = means" , "What Orwell's animals were" , "Match; peer" , "The same in size, amount or value, etc." .)