Pier 6, n.² — Green’s Dictionary of Slang

Pier 6 n.²

also Pier Six brawl, ...fight

[for a detailed assessment of the ety, see https://www.splicetoday.com/sports/origins-of-the-pier-six-brawl]

(US und.) a brawl, often of a highly unskilled professional boxing match.

1929		Bayonne Times (NJ) 8/7: The fight should develop into a real pier six brawl, as both boys are sluggers.
1929		Standard Union (NY) 19 Nov. 10/7: The semi-final [...] will be a Pier six fight.
1949		Gumps [synd. cartoon] Then [...] Countess de Bulge barged in and started a pier six brawl.
1957		W.R. Burnett Underdog 19: Big brawl. A real Pier 6. Disturbing the peace, assault and battery—you know.