Green’s Dictionary of Slang

(US black gang) to start a fight; as n., a fist fight.

1985		T.R. Houser Central Sl. 27: head up A situation where a fight between individuals is conducted one-to-one without the aid of weapons [...] A straight-out fist fight.
1991		L. Bing Do or Die (1992) 25: There’s only a couple of people I can count on here [...] If anybody try to head up with me, I got ’em.