The little dude in blue punches (though weakly) the taller man in green, and apparently connects with his adversary's chin, but it's himself (the blue-parka aggressor) who falls. Strange, and sad!
Anyway, now that I've seen Brawl at Cell Block 99 (
https://www.rooshvforum.com/thread-18972-post-1671021.html#pid1671021 ), I know that punches are almost useless, the real thing are, forearm swipes at elbows and knees. I mean, watch Vaughn calmly fighting (or should I say, dismembering his foes, bare-handed) in the movie, it's quite something! Even Little Dark would puke...