Early career Ulberg made his MMA debut in 2011 for the King of the Door promotion when he faced Kaota Puna and secured a second round knockout in his first professional fight.
Dana White's Contender Series Ulberg competed at
Dana White's Contender Series 34 on 4 November 2020 and earned himself a
UFC contract via a first round knockout of Bruno Oliveira.
Ultimate Fighting Championship Ulberg made his UFC debut on 6 March 2021 at
UFC 259 where he faced
Kennedy Nzechukwu. Ulberg had Nzechukwu in trouble early with a flurry of strikes, but quickly became exhausted and ultimately lost the fight via knockout in the second round. This fight earned him the
Fight of the Night award. Ulberg faced
Fabio Cherant on 12 February 2022 at
UFC 271. He won the fight via unanimous decision. Ulberg faced
Tafon Nchukwi on 25 June 2022, at
UFC on ESPN: Tsarukyan vs. Gamrot. He won via TKO in the first round. Ulberg faced
Nicolae Negumereanu on 12 November 2022, at
UFC 281. He won the fight via knockout in the first round. Ulberg faced Ihor Potieria on 13 May 2023, at
UFC on ABC 4. He won the fight via technical knockout in the first round. This win earned him the
Performance of the Night award. Ulberg faced
Da Un Jung on 10 September 2023, at
UFC 293. He won the fight via a rear-naked choke submission in round three. Ulberg was scheduled to face
Dominick Reyes on 20 January 2024, at
UFC 297. However, in late December 2023, it was announced that match was off due to an injury sustained by Ulberg. The pair was rescheduled to meet at
UFC on ESPN 54 on 30 March 2024. However, on 23 January it was announced that Reyes had withdrawn from the fight and was replaced by
Alonzo Menifield. On 20 February 2024 it was reported that the fight against Menifield was rescheduled for
UFC on ESPN 56 on 11 May 2024. Ulberg knocked out Menifield 12 seconds into the first round. This fight earned him another
Performance of the Night award. Ulberg was scheduled to replace
Khalil Rountree Jr., and face former
UFC Light Heavyweight champion
Jamahal Hill on 29 June 2024, at
UFC 303. However, Hill withdrew due to injury, and was replaced by
Anthony Smith. Subsequently, one week before the event, Ulberg pulled out of the bout due to injury and was replaced by
Roman Dolidze. Ulberg faced
Volkan Oezdemir on November 23, 2024, at
UFC Fight Night 248. He won the fight by unanimous decision. Ulberg faced former
UFC Light Heavyweight champion
Jan Błachowicz on March 22, 2025 at
UFC Fight Night 255. He won the close fight by unanimous decision. 8 out of 12 media outlets scored the bout for Ulberg. Ulberg faced former
UFC Light Heavyweight Championship challenger
Dominick Reyes in the main event on 28 September 2025 at
UFC Fight Night 260. He won the fight via knockout in round one. This fight earned him another
Performance of the Night award. Ulberg faced former
UFC Light Heavyweight Champion Jiří Procházka in the main event of
UFC 327 on 11 April 2026, in Miami, Florida for the vacant UFC Light Heavyweight Championship. He won the championship by knockout in the first round despite suffering a leg injury during the bout. This fight earned him a $100,000
Performance of the Night award. On 18 April 2026, it was reported that Ulberg tore his
ACL and will be sidelined from competition for an undetermined amount of time. == Championships and accomplishments ==