SALT LAKE CITY -- There have been a lot of special nights over the course of Justin Gaethje's career. UFC 291, though, has to be at the very top.

In his 29th professional fight on Saturday, Gaethje claimed the BMF title with a highlight-reel head-kick knockout of Dustin Poirier at the minute mark of the second round. Gaethje avenged a TKO loss to Poirier the first time they met in 2018 and likely earned himself a lightweight title shot in early 2024.

"This is unlike any other sport on earth, because you barely get a chance at redemption," Gaethje said. "We take a loss, we have to sit at home and let it eat away at us. We usually never get that chance. So, to come back and prove myself -- I believed in myself the whole time."

The finish was eerily reminiscent of the head kick Leon Edwards used to upset Kamaru Usman in their welterweight championship fight in August inside Salt Lake City's Delta Center. Gaethje threw out his jab and followed with a high head kick, which caught Poirier flush as he dipped away from the punch.

The BMF title was originally created in 2019, when Jorge Masvidal fought Nate Diaz in the main event of UFC 244 in New York City. Masvidal never defended the symbolic title, but he did retire in April, opening the door for the UFC to book its second BMF title fight.

Gaethje (25-4) is now tied for the fifth-most knockout finishes in lightweight history with six. He went through some adversity in the opening round before the finish, when Poirier opened a cut over his left eye with straight left hands. Gaethje blinked away the punches and appeared visibly bothered, but he eventually wiped the blood away and continued.

The finish caught the attention of former double champ Conor McGregor, who quickly extended a challenge to Gaethje on social media. McGregor is expected to face Michael Chandler at some point following the conclusion of "The Ultimate Fighter" reality show, which the two filmed together in Las Vegas earlier this year.

In his tweets, McGregor appeared to indicate he would rather fight Gaethje than Chandler.

"Justin, I'll slap you around," McGregor wrote on Twitter. "I'm the real BMF, he can fight for pennies if he wants but I want spirits, I call the shots, I'm in it to launch shots, f--- Chandler, you want it call for it."

Gaethje has expressed interest in a fight against McGregor previously, but his main focus has been UFC gold. He won the UFC's interim title in 2020 by defeating Tony Ferguson but failed to unify the belt in a title fight against Khabib Nurmagomedov later that year. He challenged then-champion Charles Oliveira for the title again in 2022 and lost via submission.

Current champion Islam Makhachev is scheduled to defend the belt in a rematch against Oliveira at UFC 294 on Oct. 21.

"I want to fight for the world championship," Gaethje said. "These guys are fighting in October. Win, lose or draw, I'll give max effort. I'm willing to roll the dice every day."

Poirier (29-8) suffered his first knockout loss since 2016. Saturday marked his first appearance of 2023. In his previous bout, he submitted Chandler at UFC 281 in November.