Roman Kryklia

In October 2012, Kryklia made his professional debut against Tomáš Možný at Nitrianska noc bojovníkov 2012. He won the fight by decision. Kryklia would go on to amass a 4-3 record, winning four of his next seven fights. In January 2015, he participated in the Yangame's Fight Night 2 light heavyweight tournament.[6] He won both the semifinal bout against Jiří Stariat and the final bout against Radovan Kulla by decision.[7]

After his first tournament title win, Krylia won three of his next four fights, including notable victories over Igor Mihaljević[8] and Sergej Maslobojev. He then took part in the 2015 Tatneft Cup heavyweight tournament, scoring knockouts of Claudiu Istrate in the semifinals and Daniel Lentie in the finals.[9]

Two months later, Krylia would sign with the biggest kickboxing promotion in Europe to participate in their SUPERKOMBAT Heavyweight Grand Prix. He won a unanimous decision against Ivan Pavle in the semifinals, but lost to Tarik Khbabez by decision in the finals.[10]

After losing to Khabez, Kryklia went on a thirteen fight winning streak, which began with decision wins against Konstantin Gluhov and Jahfarr Wilnis. In June 2016, he won the A1 WGP qualification tournament by knocking out Thomas Vanneste in the semifinals, and by forcing Daniel Lentie to withdraw at the end of the first round in the final. In the semifinals of the A1 Grand Prix itself, Kryklia faced Daniel Lentie for the third time in his career, and won for the third time as well, beating Lentie by decision. He won the tournament with a first-round TKO of Arnold Oborotov.[11]

Kryklia vs. Kwasi in K-1

Just two weeks later, Kryklia entered the 2016 K-1 Europe heavyweight tournament. Kryklia won the quarterfinals against Bosnian Bahrudin Mahmić, semifinals against Atha Kasapis and finals against Fabio Kwasi in the same manner - knocking all three with a knee strike.[12] For his last fight of 2016, Kryklia was scheduled to fight Stéphane Susperregui at Nuit des Champions 2016. He won the fight by majority decision.[13]

During Monte Carlo Fighting Masters, Kryklia fought Fabrice Aurieng for both the Prince Albert's Cup and the Monte Carlo FM heavyweight title. He won the fight by TKO, after Aurieng's corner threw in the towel in the second round.[14]

In December 2017, Kryklia fought in the Kunlun Fight heavyweight tournament, held at the KLF 68 event. He won the quarterfinal bout against Ning Tianshuai by a first-round TKO and the semifinal bout against Felipe Micheletti by unanimous decision. He lost the final fight against Iraj Azizpour by an extra round decision, despite coming into the fight as a favorite.[15]

Kryklia fought Yuksel Ayaydin at MFC 7, in Ayaydin's retirement fight, winning the fight by decision.[16] He afterwards fought Daniel Svkor for the WAKO World heavyweight tile, winning by a second-round knockout.[17]

In the semifinals of the 2018 FEA World Grand Prix, Kryklia was scheduled to fight a rubber match with Tomáš Hron, with each fighter holding a win over the other. He won the fight by unanimous decision, and went on to face Tsotne Rogava in the final. The fight with Rogava went into an extra round, after which Kryklia won a decision.[18]

At Kunlun Fight 80, Kryklia once again fought in the KLF heavyweight tournament. He defeated Martin Pacas by unanimous decision in the quarterfinal, and Rade Opacic by a second round TKO in the semifinal, before fighting a rematch with Iraj Azizpour in the finals. Kryklia was more successful in their second fight, winning a unanimous decision.[19]

On November 16, 2019, Roman Kryklia defeated Tarik Khbabez by TKO to become the inaugural ONE Light Heavyweight Kickboxing World Champion.[20]

Kryklia was expected to defend his belt against Andrei Stoica at ONE Infinity 1, but the light heavyweight title fight postponed due to coronavirus.[21][22] Kryklia was rescheduled to defend the ONE Light Heavyweight Kickboxing World Championship against Murat Aygün at ONE Championship: Big Bang on December 4, 2020.[23] The fight with Aygun fell through, as one of Kryklia's corner-men tested positive for COVID-19.

Accordingly, Aygun received a new opponent, while Kryklia was scheduled to fight the mandatory challenger Andrei Stoica, who took the fight on short notice being announced only a few days before the match,[24] at ONE Championship: Collision Course.[25] At the official weigh in, Kryklia weighed more than Stoica.[26] Eventually, the fight was won by Kryklia by unanimous decision, who was in control during the match.[27][28]

Kryklia was scheduled to make his second ONE Kickboxing Light Heavyweight title defense against Murat Aygün at ONE Championship: NextGen on October 29, 2021.[29] However, Aygün was pulled from the fight and Kryklia was instead scheduled to face Iraj Azizpour for the inaugural ONE Kickboxing Heavyweight World Championship.[30] However, due to an undisclosed medical issue, Kryklia withdrew from the fight.

Kryklia was rebooked against Murat Aygün for January 14, 2022 at ONE: Heavy Hitters.[31] The fight was later postponed for ONE: Full Circle on February 25, 2022.[32] Kryklia defeated Aygün via first-round knockout.[33]

Kryklia faced Guto Inocente in the semifinals of the ONE Heavyweight Kickboxing World Grand Prix Tournament at ONE 161 on September 29, 2022.[34] He won the fight by a first-round knockout. Kryklia knocked Inocente down twice before the one-minute mark of the opening round, which prompted the referee to wave the fight off.[35]

Kryklia was booked to face Iraj Azizpour in a trilogy bout in the finals of the ONE Heavyweight Kickboxing World Grand Prix Tournament at ONE 163 on November 18, 2022.[36] He won the fight by a second-round knockout, after having been dropped by Azizpour in the opening frame.[37]

Kryklia was expected to make his third ONE Light Heavyweight Kickboxing World Championship defense against Françesko Xhaja at ONE Fight Night 12 on July 14, 2023.[38] The title bout was postponed due to an undisclosed injury on June 30.[39]