Fred Paz was closing up Tuesday night at Kwik Check Cashing in Linden when he says the man dropped down from the ceiling and waved his arm in a stabbing motion.
Paz told The Star-Ledger of Newark he struck the intruder in the face with a fire extinguisher and sprayed him with foam.
The 30-year-old says he triggered the alarm as he ran from the store and locked the burglar inside.
The suspect was gone when police arrived.
Information from: The Star-Ledger, http://www.nj.com/starledger