This MMA fighter took a punch so hard he hit the canvas and went stiff

Goodness was this scary.

Late in the first round at Hard Knocks in Calgary, Alberta, Canada, MMA fighter Sean Michaels dropped opponent Joe Mapanda with a vicious right hook that immediately ended the fight.

Related: This vicious left hook came out of nowhere and put this MMA fighter to sleep 

Michaels and Mapanda squared off in the main event, but Michaels ended the fight in one punch.

Michaels, who goes by HBK, improved his record to 3-1 in amateur competition. Mapanda dropped to 3-3.

(h/t Bleacher Report)