Control playing piece, pinning one knight (8)

I believe the answer is:

dominion

I'm a little stuck... Click here to teach me more about this clue!

'control' is the definition.
(I know that dominion is a type of control)

'playing piece pinning one knight' is the wordplay.
'playing piece' becomes 'domino' (I can't explain this - if you can you should give a lot more credence to this answer).
'pinning' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'knight' becomes 'n' (chess abbreviation).
'domino' placed around 'i' is 'dominio'.
'dominio'+'n'='DOMINION'

Can you help me to learn more?

(Other definitions for dominion that I've seen before include "Supremacy" , "Sovereignty, control" , "eg Canada" , "Area of control" , "Government" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.