Two syllables that say what they mean: "knock" and "out." Knock as in "clobber." Out as in "out of consciousness."
Generally we think of the knockout as the crowning, climatic moment. It often comes from a stunning final blow at the end of a hard-fought battle.
But not always. Sometimes the circumstances are a bit...well, odder than that.
Here now are 25 of the most bizarre knockout videos you'll ever see.