Multiple sites have this, here is but one (no pre-existing SDMB threads as far as I could see)
Zelenoff has been trolling Wilder for a long time and threatened his child, which was the last straw for Wilder. It’s funny, in a pathetic way. Or pathetic in a funny way.
He was caught off guard!? Between accepting the challenge, driving to the gym, changing into fight trunks, strapping on the gloves, and stepping into the ring with a professional fighter who hates you, you’d think this guy had ample warning that he was about to get punched in the face.