Dustin Poirier, Justin Gaethje to run it back in UFC 291 main event

Flashback: The first time Justin Gaethje and Dustin Poirier fought (0:30)

Turn back the clock to 2018, when Dustin Poirier beat Justin Gaethje via TKO in their first meeting. (0:30)

Former UFC interim lightweight champions Dustin Poirier and Justin Gaethje will square off for the second time in a five-round main event at UFC 291, UFC president Dana White announced on Tuesday.

The 155-pound bout is being promoted as the second "BMF" title fight in UFC history, following the retirement of original "BMF" champion Jorge Masvidal in April. The UFC created the title in 2019, as a fun way to promote a non-title main event between Masvidal and Nate Diaz in New York. Masvidal claimed the belt via TKO and remained the honorary "BMF," despite ending his career on a four-fight skid.

The UFC 291 pay-per-view event takes place on July 29 at Vivint Arena in Salt Lake City. It will mark the UFC's second trip to the city in the last 12 months.

The Poirier-Gaethje bout is a rematch of their April 2018 slugfest, which Poirier won by fourth-round knockout.

The "BMF" theme resonates strongly throughout the UFC 291 main card. In addition to the fan-pleasing main event, the card features the light heavyweight debut of former middleweight champion Alex Pereira (7-2), who will move up to face former light heavyweight champion Jan Blachowicz (29-9-1) in the co-main event.

Additionally, former interim lightweight champion Tony Ferguson (25-8) will take on Bobby Green (29-14-1). Middleweight Paulo Costa (14-2) will fight for the first time since last July against Ikram Aliskerov (14-1) and Michael Chiesa (16-6) will face Kevin Holland (24-9) in a clash of welterweight contenders.

The winner of the Poirier-Gaethje rematch will likely earn a future shot at the 155-pound championship. Poirier, 34, came up short in a bid for the title against Charles Oliveira in late 2021, but still holds a very strong resume, with two wins over Conor McGregor and a victory over Michael Chandler in 2020.

Gaethje, 34, is also just one year removed from an unsuccessful title fight against Oliviera in May 2022. He picked up a massive win over Rafael Fiziev in March.