Judy down in fist fight? (5-2)

I believe the answer is:

punch-up

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'fist fight?' is the definition.
(I've seen this before)

I don't understand how the rest of the clue works.

(Other definitions for punch-up that I've seen before include "An informal fist-fight or brawl - strike vertically?" , "Fisticuffs incident" , "Fist fight" , "An informal fight, with vertical blows?" , "An informal brawl, a fight with fists" .)

I've seen this clue in The Irish Independent.

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