You can't do better than master this (5)

I believe the answer is:

piece

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'you can't do better than master this' is the definition.
The definition suggests a singular noun which matches the answer.

This is all the clue.

Can you help me to learn more?

(Other definitions for piece that I've seen before include "rook, perhaps" , "Portion, bit" , "Portion; musical work" , "A part of something" , "Queen on board, perhaps" .)

I've seen this clue in The Globe and Mail.

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