Thomas Petersen, head-and-shoulders portrait
The Train

Thomas Petersen

Heavyweight
Pressure boxer
Record Record: 11-5-0
Wins
11
Losses
5
Draws
0
7KO/TKO
1Sub
3Dec
View full record ↓

Vitals

Height, reach, and career background.

Age31
Height1.85 m
Reach188 cm
NationalityUnited States
TeamThe Striking Institute
Weight classHeavyweight
Active2019-present

Record

Tap any fight for the breakdown.

LossSUB
Opponent: Valter Walkercalf slicerR1 1:32
UFC Fight Night: Ankalaev vs. Guskov
25 Jul 2026

Valter Walker pulled guard in the opening clinch and chased a heel hook, then adjusted to a calf slicer when Thomas Petersen began to free his leg, forcing the tap at 1:32 of round one.

Key moments

  • Walker closed the distance and pulled guard as soon as the pair clinched.
  • Petersen defended the initial heel-hook attempt by rolling and extracting his leg.
  • Walker trapped the calf, increased the pressure, and forced the tap.
WinDEC
Opponent: Guilherme PatmajorityR3 5:00
UFC Fight Night 272 - Moicano vs. Duncan
4 Apr 2026

Petersen's latest result was a majority decision win over Pat after three rounds. It was the kind of grinding heavyweight result that reinforced his ability to bank rounds even when the finish does not show up.

Key moments

  • Won a majority decision over fifteen minutes.
  • Stayed composed through a competitive three-round heavyweight fight.
  • Returned to the win column after the Petrino loss.
LossKO
Opponent: Vitor PetrinopunchesR3 0:26
UFC Fight Night 261 - Oliveira vs. Gamrot
11 Oct 2025

Petersen was close to reaching the cards against Petrino, but the fight turned sharply in the final round when he was knocked out with 26 seconds gone.

Key moments

  • Lost by third-round knockout.
  • The stoppage came 26 seconds into round three.
  • Saw a potential decision fight end suddenly late.
WinDEC
Opponent: Don'Tale MayesunanimousR3 5:00
UFC on ESPN 67 - Sandhagen vs. Figueiredo
3 May 2025

Petersen managed the Mayes fight over the full fifteen minutes and left with a unanimous decision.

Key moments

  • Won a unanimous decision after three rounds.
  • Rebounded directly from the Gaziev loss.
  • Added another UFC win over an established heavyweight.
LossTKO
Opponent: Shamil GazievpunchR1 3:12
UFC Fight Night 250 - Adesanya vs. Imavov
1 Feb 2025
WinDEC
Opponent: Mohammed UsmanunanimousR3 5:00
UFC on ESPN 60 - Lemos vs. Jandiroba
20 Jul 2024
LossDEC
Opponent: Jamal PoguesunanimousR3 5:00
UFC Fight Night 235 - Dolidze vs. Imavov
3 Feb 2024
WinSUB
Opponent: Chandler ColekeylockR2 1:08
Dana White's Contender Series - Contender Series 2023: Week 4
29 Aug 2023
WinKO
Opponent: Richard FosterpunchesR1 3:48
LFA 150 - Farias vs. Sweeney
13 Jan 2023
WinTKO
Opponent: Kory MoegenburgpunchesR2 3:14
LFA 142 - Amorim vs. Nichols
16 Sep 2022
LossTKO
Opponent: Waldo Cortes-AcostapunchesR3 4:53
LFA 129 - Petersen vs. Cortes-Acosta
15 Apr 2022
WinTKO
Opponent: Vernon LewispunchesR1 1:02
LFA 113 - Lewis vs. Petersen
30 Jul 2021
WinTKO
Opponent: Odell PantinpunchesR1 3:33
LFA 104 - McKenzie vs. Phillips
16 Apr 2021
WinKO
Opponent: Richard LuispunchR1 0:19
LFA 97 - Browne vs. Estrazulas
15 Jan 2021
WinTKO
Opponent: Brian PetersonpunchesR1 1:52
LFA 82 - Polizzi vs. Pogues
21 Feb 2020
WinTKO
Opponent: B.J. LacypunchesR1 2:12
Driller Promotions - Mecca 16
21 Dec 2019

J. Lacy at Mecca 16.

Key moments

  • Won his professional debut by TKO at 2:12 of round one.
  • The fight took place on the Mecca 16 card promoted by Driller Promotions.
  • It was the first of Petersen's many opening-round heavyweight finishes.

The Read

Style, strengths, and defining traits.

On 25 July 2026 at UFC Abu Dhabi, Thomas Petersen lost to Valter Walker by Submission (calf slicer) · R1 1:32.

Petersen fights like a natural heavyweight pressure boxer, leaning on his hands and forward drive rather than a layered kicking game. Most of his best wins have come once he starts putting opponents on the fence and forcing them to absorb long punching sequences.

The recent UFC stretch has been mixed, but it has still shown that he can hang in competitive three-round heavyweight fights. Decision wins over Mohammed Usman, Don'Tale Mayes and Guilherme Pat have kept him relevant even after the knockout and stoppage losses on the other side of the ledger.