Knockout round involving locals? (3,5)

I believe the answer is:

pub crawl

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'knockout' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe they are linked in a way I don't understand?

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for pub crawl that I've seen before include "Night out (ending on all fours?)" , "A local expedition?" , "Drinking tour" , "Bender" , "Local tour" .)

I've seen this clue in The Telegraph.

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