Boxing Champ Gennady Golovkin -- I WILL BREAK MITTS ... Destroys Training Session

You're about to feel very sorry for a pair of mitts ... 'cause here's freakish video of middleweight boxing champ Gennady "GGG" Golovkin absolutely DESTROYING two inanimate objects in a single training session.

GGG (32-0, 29 KO's) is preparing for a huge fight against Willie Monroe Jr. in L.A. this weekend, and decided to scare the living crap out of Willie's family by stepping into the ring Wednesday with his trainer Abel Sanchez for a mitt session.

Golovkin -- who's basically the anti-Floyd, having KO'd 19 dudes in a row -- is throwing absolute FREAKIN' BOMBS in there ... at times looking like he's breaking the will of the veteran trainer.