They elicit a visceral reaction from an audience like nothing else in combat sports. Quick knockouts are a staple of the Ultimate Fighting Championship and date back to UFC 1 on Nov. 12, 1993 in Denver. There, nearly 8,000 spectators at McNichols Arena let out a collective groan and gasp when Gerard Gordeau sent Teila Tuli’s tooth flying with a kick to the face just 26 seconds into the first-ever fight inside the Octagon. It served as a wakeup call for all those who had considered climbing into the cage and a rallying cry for those who deemed mixed martial arts too barbaric for public consumption.