While studying in a technical school, he was part of the national wrestling team where he won medals in the Polish junior and youth championships.

He transitioned to mixed martial arts in 2011, training under, Andrzej Kościelski, World Champion in wrestling.

[9] In 2012, he won a gold medal in the 70 kg category of the European Amateur MMA Championships (Brussels), defeinding his title the following year (Budapest).

[10] He won the gold medal at the Polish grappling championships in the purple belt category (Luboń) in 2013 and 2014.

[10] He made his professional MMA debut on February 4, 2012, at XFS Night of Champions, defeating Chechen Arbi Shamayev.

[13] On September 13, 2014, he made his promotional debut for Cage Warriors, defeating Welshman Tim Newman in the 1st round with a heel hook submission at CW 72.

[15] At KSW 30 on February 21, 2015, he defeated Brazilian Rodrigo Cavalheiro Correia by technical knockout six seconds before the final bell.

[17] At KSW 32: Road to Wembley, Mateusz defeated Marif Piraev via TKO in the second round, improving his record to 10-0.

[20][21] At KSW 36: Materla vs. Palhares on October 1, 2016, he defended his title via heel hook against Renato Gomes Gabriel in the second round.

[26] The bout was stopped in the second round when accidental eye pokes left Parke unable to continue.

Gamrot was subsequently fined 30% of his purse and Bilman was handed a two-year ban from KSW events.

[28] On December 1, 2018, at KSW 46: Narkun vs. Khalidov 2, he fought for a second belt, this time for the KSW Featherweight Championship, against submission specialist Kleber Koike Erbst, where he won the bout after a five-round domination, capturing the organization's second crown.

[29] On May 17, 2019, in a video on Borys Mankowski's YouTube channel, Gamrot announced that he had vacated his two belts and did not renew his contract with KSW.

[37] Gamrot, as a replacement for Renato Moicano, was scheduled to face Magomed Mustafaev at UFC Fight Night: Ortega vs.

[50] As the first bout of his new four-fight contract, Gamrot faced Carlos Diego Ferreira on December 18, 2021, at UFC Fight Night: Lewis vs.

[70] Gamrot was reportedly going to face Rafael Fiziev in a rematch on February 1, 2025 at UFC Fight Night 250.