World Extreme Cagefighting

Jewtuszko then signed for the WEC and made his debut at WEC 50 - where he was regarded as a heavy underdog ^[2][3][4] - against Anthony Njokuani. Jewtuszko went on to defeat his opponent via TKO (punches) early in the first round. By doing so, he was awarded the Knockout of the Night bonus.^[5] Maciej was scheduled to make his second World Extreme Cagefighting appearance against Ricardo Lamas at WEC 53,^[6] but had to withdraw as he suffered a broken hand during training.^[7]

Ultimate Fighting Championship

In October 2010, World Extreme Cagefighting merged with the Ultimate Fighting Championship. As part of the merger, all WEC fighters were transferred to the UFC.^[8]

Jewtuszko faced Curt Warburton on February 27, 2011, at UFC 127^[9] and suffered his first loss of his professional career via unanimous decision. After the loss, Jewtuszko was released from the promotion.^[10]

Konfrontacja Sztuk Walki

In September 2011, he signed a contract with the largest Polish MMA organization, Konfrontacja Sztuk Walki.^[11] On November 26, 2011, during the KSW 17: Revenge, despite being the favorite, he lost to Artur Sowiński in the 1st round by knockout.^[12]

On February 25, 2012, he defeated the Ultimate Fighter contestant Dean Amasinger by TKO in the 1st round at the KSW 18.^[13] For this victory, he received a financial bonus for the "knockout of the evening".^[14] In the same year - on December 1, he fought a rematch with Artur Sowiński at the KSW 21 for the KSW Lightweight Championship, in which he defeated Sowiński after a spectacular fight in the 2nd round by choking him unconscious via D'arce choke.^[15]

After defeating Vaso Bakočević in a non-title bout at KSW 28: Fighters Den, in 2015, he vacated the lightweight championship belt, changing the weight category to welterweight (-77 kg).^[16] In the first fight in the welterweight division at KSW 31: Materla vs. Drwal, he lost to former PLMMA champion Kamil Szymuszowski by unanimous decision, who was a replacement for the injured Robert Radomski.^[17]

At the KSW 34: New Order, which took place on March 5, 2016 in Warsaw, he faced the experienced Krzysztof Kułak,^[18] winning after Kułak submitted to ground and pound in the second round.^[19]

On October 22, 2017 at KSW 40: Dublin in the capital of Ireland, he crossed gloves with the contender for the KSW welterweight title, David Zawada.^[20] After a dynamic fight focused mainly on stand up, he lost by unanimous decision of the judges.^[21]

Fight in FEN

In January 2019, it was announced that he had signed a contract with Fight Exclusive Night.^[22] In his debut, he was supposed to face Norman Parke, but the fight did not take place.^[23] On June 15, 2019, he made his debut in the main event of the FEN 25, which took place at the Amphitheater in Ostróda, he rematched with Vaso Bakočević.^[24] The competitor from Montenegro successfully took revenge on the "Iroquois", defeating him by technical knockout when he did not advance to the next round due to a knee injury.^[25]

Jewtuszko returned five years later to face Marius Žaromskis in a retirement bout for both men on March 16, 2024 at KSW 92: Wikłacz vs. Jojua, winning the bout via unanimous decision, for the first time in his career.^[26]