MMA World Left Stunned By Sudden Passing of UFC Fighter Allan Nascimento

On Monday, the combat sports world was rocked by the news that UFC flyweight Allan Nascimento had died in his sleep.

A veteran of 29 professional MMA bouts, Nascimento last competed in June when he met Mitch Raposo at UFC Vegas 119 and lost a split decision that ended a run of four-straight victories.

A member of Sao Paulo’s Chute Boxe Diego Lima, “Puro Osso” began his professional MMA career in 2011 and joined the UFC in 2021.

UFC & Charles Oliveira Pay Tribute to Allan Nascimento

Following initial reports of Nascimento’s passing, official UFC social media accounts shared tributes to the Brazilian fighter and confirmed that he’d suffered an apparent heart attack while he was sleeping.

This morning, Monday, August 3rd, our beloved flyweight fighter, Allan Nascimento, was found unresponsive after suffering an apparent heart attack in his sleep. Despite the efforts of the responding medical team, he was pronounced deceased at the scene.

Our thoughts and deepest… pic.twitter.com/vlaBaBOyJr
— UFC (@ufc) August 3, 2026

Among the fighters to pay tribute to Nascimento was his Chute Boxe teammate Charles Oliviera, who memorialized the 34-year-old in several posts on his Instagram story.

One of several tributes that Charles Oliveira shared via his Instagram story. | (Instagram)

One of the videos shared by Oliveira was himself and Nascimento leaving the cage in the aftermath of his most recent fight at UFC 326, where he avenged a previous loss to Max Holloway and claimed the UFC’s “BMF” belt in the process.

“Puro Osso” Went 22-7 During Nearly 15-Year MMA Career

Best known for his skills on the mat, Nascimento secured 15 of his 22 career MMA victories via submission.

Beginning his MMA career on the regional scene in his native Brazil in 2011, “Puro Osso” initially
went 7-0 before he dropped a decision to Will Campuzano in a flyweight title bout with Legacy Fighting Championship, which would eventually go on to merge with Resurrection Fighting Alliance and form current top United States promotion Legacy Fighting Alliance.

That first loss in 2013 kicked off a busy year for Nascimento. He rebounded with three-straight submissions and dropped a decision to future UFC veteran Ricardo Ramos but closed out the year with another submission victory, competing a total of six times in just over seven months.

Allan Nascimento's UFC Run Included Two "Performance of the Night" Bonuses

Nascimento brought a 17-4 record into a Dana White’s Contender Series opportunity in 2018, initially missing out on a UFC contract when he dropped a split decision to his countryman Raulian Paiva.

“Puro Osso” returned just under three years later to pick up another submission in Brazil before making his UFC debut at UFC 267, where he lost another split decision to Tagir Ulanbekov.

Undeterred by a loss in his promotional debut, Nascimento rebounded with four-straight victories and secured “Performance of the Night” bonuses for his submissions of Carlos Hernandez and Cody Durden before he came up short against Raposo in June.

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