[6] Emmett is also an accomplished Brazilian jiu-jitsu grappler, he won a World championship in the blue belt no-gi division.

[6] After compiling an amateur record of 2–0, Emmett started his professional MMA career on October 8, 2011, and made his debut in Capitol Fighting Championship as a Featherweight.

He broke his hand in the first round and continued with the fight and managed to earn his first win by unanimous decision.

[14] After he secured the championship belt, Emmett didn't return to compete until almost one year later on October 3, 2015, at KOTC promotion, facing Rocky Johnson.

[18][19][20] Emmett suffered a compound fracture on his left right finger from catching Tuck's spinning back kick[21] and the referee halted the fight briefly prior to restarting.

[25] The three round fight was a back and forth battle and judges awarded the win to Emmett via unanimous decision.

[28] Emmett faced Felipe Arantes in a featherweight bout on October 21, 2017, at UFC Fight Night 118.

[30] Emmett dedicated this win to his friend's son, who has heart condition, at the age of 11 and has gone through an experimental surgery.

[31] Emmett faced Ricardo Lamas on December 16, 2017, at UFC on Fox: Lawler vs. dos Anjos.

[34] Emmett faced Jeremy Stephens at UFC on Fox 28, which took place on February 24, 2018, in Orlando, Florida.

[36] As a result, Emmett was sidelined for the remainder of 2018, after undergoing successful surgery to correct facial injuries sustained during the Stephens fight.

[46] However, on April 9, Dana White, the president of UFC announced, that this event was postponed, and the bout cancelled.

[45] As the first fight of his new prevailing contract, Emmett faced Shane Burgos on June 20, 2020, at UFC on ESPN: Blaydes vs.

[50] Emmett was sidelined for the remainder of 2020 and most of 2021, recovering from a litany of injuries to his left leg sustained in the fight, including an ACL tear.

[53] Emmett faced Calvin Kattar on June 18, 2022, in the main event at UFC on ESPN 37.

[60] However, the promotion later announced, that the bout was shifted to headline UFC on ABC: Emmett vs. Topuria on June 24, 2023.

[68] Emmett is scheduled to face Lerone Murphy on April 5, 2025 in the main event at UFC Fight Night 256.