It was a massive upset in the eyes of bookmakers and UFC commentators, making the strike even more staggering.
It is now four losses for Edgar in his last five fights, leaving his career at a crossroads.
Incredibly his knockout was arguably trumped by several other stoppages on an insane card that featured seven knockout results.
Chris Barnett put his name up in headlines with a sweet spinning wheel kick that dropped his opponent.
It was followed by a stinging knockout punch from Curtis Scott and a thunderous debut by kickboxer Alex Pereira, who pulled off a vicious KO victory with a flying left knee strike.
The UFC now turns its attention to Sunday's fight night event between Max Holloway and Yair Rodriguez and December's UFC 269 card featuring Charles Oliveira's fight with Dustin Poirier.
