UFC fighter Steven Peterson's spinning backfist was so vicious there's buzz it could be "KO of the Year" ... except the guy who landed the crushing blow says he doesn't deserve it.
That honor is reserved for Gamebred ... Peterson tells TMZ Sports.
"Man, I would love to get knockout of the year, but I can't beat Jorge Masvidal's knockout. You can't beat the flying knee knockout. I bet I'll get runner up, and I'm happy with that. I'm ecstatic to have runner up behind Jorge Masvidal."
Of course, Masvidal knocked out Ben Askren with a flying knee 5 seconds into their July fight.