(Source: Jeff Bottari/Getty Images)SALT LAKE CITY -- There have been a lot of memorable nights throughout Justin Gaethje's career. UFC 291, though, has to be at the very top. In his 29th professional fight on Saturday night, Gaethje claimed the BMF title with a highlight-reel head-kick knockout of Dustin Poirier at the one-minute mark of the second round. The victory earned Gaethje revenge for a TKO loss he suffered to Poirier the first time they met in 2018 and likely earned him a lightweight title shot in early 2024.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. 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 eventually wiped the initial 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. Gaethje has expressed interest in a fight against McGregor, but his primary 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.Poirier (29-8) suffers his first knockout loss since 2016. Saturday marked his first appearance of 2023. Most recently, he submitted Chandler at UFC 281 in November.