UFC 291: Justin Gaethje KOs Dustin Poirier for BMF belt, calls for lightweight title shot

As of UFC 291, Justin Gaethje is a certified BMF.

The fan favorite lightweight notched the biggest win of his career with a second-round KO of Dustin Poirier, winning the honorary "BMF" title with a head kick that sent his opponent flat. Referee Herb Dean had to leap between the two fighters to stop Gaethje from doing further damage.

Gaethje celebrated the win with a backflip off the fence.

Gaethje had performed well in the first round, landing 33 of 56 significant strikes to Poirier's 27 of 51.

Over the last few years, Gaethje has been a participant in the most competitive division in UFC, with the likes of Poirier, Islam Makhachev, Charles Oliveira, Michael Chandler and more competing for a belt currently held by Makhachev.

Before Saturday, Gaethje's only win among that wave had been Chandler, but rocking Poirier could move him up a place in line to challenge Makhachev. Oliveira, the former champ, is currently scheduled to rematch Makhachev at UFC 294 in Abu Dhabi on Oct. 21.

"You know what I want to do next. I want to fight for the world championship," Gaethje said after the fight. "I want to prove I'm the best in the world. Win, lose or draw, max effort is what you're going to get from me. Luck and chance are a factor and I'm willing to roll the dice any f***ing day."

Gaethje lost his first title shot against Oliveira, who missed weight before the fight, by first-round submission. Since then, he has defeated Poirier and defeated by majority decision Rafael Fiziev in a bout that won Fight of the Night at UFC 286.