Don Diego Gromda: The Undefeated Champion’s Journey

Early Life and Background

Born on July 18, 1991, in Lubaczów, Poland, Mateusz Kubiszyn developed an early passion for combat sports. His journey into martial arts began at the tender age of seven when he first enrolled in karate shotokan classes, which he continued until he was 17 years old (1998-2008). During this formative period, Kubiszyn didn’t limit himself to just one discipline – he simultaneously pursued gymnastic training for six years (1999-2005) and played soccer for fifteen years (1999-2014).

This diverse athletic background laid a solid foundation for his future combat sports career. At 15, Kubiszyn discovered kickboxing, the discipline that would eventually propel him to international recognition. His natural talent and dedication to the sport quickly became apparent as he progressed through the ranks.

Beyond his fighting career, Kubiszyn has maintained a professional life as a firefighter in Rzeszów, Poland. Before this, he worked in emergency medical services in Lubaczów. This background in public service reflects his character outside the ring – disciplined, courageous, and committed to helping others.

Rise to Prominence in Kickboxing

Kubiszyn’s kickboxing career began to flourish in 2013 when he claimed his first Polish championship title in the full contact division. This achievement marked the beginning of an impressive competitive journey. The following year, his exceptional skills earned him a place on the Polish national team, setting the stage for international success.

His most significant achievement in kickboxing came in November 2015 at the WAKO World Championships in Dublin, Ireland. There, Kubiszyn conquered the 86kg full contact division, defeating fighters from Kazakhstan, Ireland, Turkey, and ultimately Russia to claim the world title. This victory established him as one of Poland’s premier combat sports athletes.

Kubiszyn would go on to claim the WAKO World Championship title two more times – in 2019 in Antalya, Turkey (91kg division) and in 2021 in Jesolo, Italy. These accomplishments cemented his legacy as one of the most decorated Polish kickboxers in history.

Professional Kickboxing Record

Dominance in Bare-Knuckle Boxing

In 2020, Kubiszyn made a pivotal career move by entering the world of bare-knuckle boxing with the Gromda organization. His debut came at Gromda 2 on August 28, 2020, where he participated in a one-night tournament. In a remarkable display of skill and endurance, Kubiszyn defeated three opponents in a single evening – Artur „Chuligan” Tomala, Rafał „Łazar” Łazarek, and Dawid „Maximus” Żółtaszek – to emerge as the tournament champion.

This impressive debut was just the beginning. On December 11, 2020, at Gromda 3, Kubiszyn faced Krystian „Tyson” Kuźma in what was billed as a clash between a technical fighter and a street brawler. Don Diego’s superior technique prevailed as he knocked out Kuźma in the third round, further establishing his dominance in the organization.

On May 26, 2023, at Gromda 13, Kubiszyn achieved his greatest accomplishment in bare-knuckle boxing by defeating Bartłomiej „Balboa” Domalik to claim the Gromda championship belt. This victory was particularly significant as both fighters entered the contest with undefeated records in bare-knuckle competition.

Since capturing the title, Don Diego has successfully defended it multiple times, most recently against Jakub „Słomka” Słomka on March 7, 2025, at Gromda 20. His perfect 10-0 record in Gromda has earned him recognition as the organization’s most dominant champion.

Bare-Knuckle Boxing Record

Fighting Style and Techniques

What sets Don Diego apart in the world of bare-knuckle boxing is his technical approach to a sport often dominated by brawlers. Kubiszyn brings his extensive kickboxing background into the bare-knuckle arena, emphasizing precision, timing, and defensive awareness.

His signature technique is the left straight punch, which he delivers with remarkable accuracy and power. This punch has been the finishing blow in several of his victories. Kubiszyn also excels at controlling distance, allowing him to evade his opponents’ attacks while setting up his own offensive combinations.

Adrian Wardęga, Kubiszyn’s coach, has praised his student’s disciplined approach: „Mateusz is not just talented; he’s one of the hardest working athletes I’ve ever trained. His success comes from his dedication to perfecting every aspect of his craft.”

This technical mastery has allowed Don Diego to remain relatively unscathed in a sport known for causing significant facial damage. While many bare-knuckle fighters suffer extensive cuts and bruising, Kubiszyn’s defensive skills have helped him minimize damage throughout his career.

Ventures Beyond Gromda

While Don Diego has made his name primarily in Gromda’s bare-knuckle boxing format, he has also tested his skills in other combat sports arenas. In 2022, he ventured into MMA with the High League organization, a Polish promotion that features both professional fighters and celebrities.

His MMA debut came on June 20, 2022, at High League 3: Extra, where he faced Denis „Bad Boy” Załęcki. Despite his limited grappling experience, Kubiszyn secured a unanimous decision victory. However, his second MMA bout against Olympic bronze medalist wrestler Damian Janikowski at High League 5 resulted in his first defeat in the sport, as Janikowski utilized his superior wrestling to control the fight.

In 2024, Don Diego signed with FAME MMA, one of Poland’s largest combat sports promotions. His debut for the organization came on October 4, 2024, at FAME: The Freak, where he faced Michał „Wampir” Pasternak in a kickboxing match with small gloves. Despite entering as a heavy favorite, Kubiszyn suffered a surprising split decision loss.

These ventures into other combat sports formats demonstrate Don Diego’s willingness to test himself and expand his skills beyond his bare-knuckle boxing comfort zone. While the results have been mixed, they have contributed to his growth as a fighter and increased his popularity among Polish combat sports fans.

Personal Life and Outside Interests

Beyond the ring, Mateusz Kubiszyn leads a life grounded in service and family values. His career as a firefighter in Rzeszów reflects his commitment to public service and his willingness to put himself at risk to help others – a quality that parallels the courage he displays in combat sports.

Kubiszyn is in a relationship with Sylwia Surówka, a bodybuilder who shares his passion for fitness and physical discipline. In 2020, the couple welcomed their daughter, Melania, into the world. Don Diego has often spoken about how becoming a father has given him additional motivation in his fighting career.

Despite his growing fame in the Polish combat sports scene, Kubiszyn maintains a relatively low profile on social media compared to many contemporary athletes. His Instagram account (@dondiego_kubiszyn) provides glimpses into his training regimen and family life but avoids the controversies and public feuds that characterize many fighters’ online presence.

When not training or working, Kubiszyn enjoys outdoor activities and spending time with his family. His disciplined approach to life extends beyond fighting – he is known for maintaining a strict diet and training schedule even when not preparing for specific competitions.

Cultural Impact and Legacy

Don Diego has played a significant role in the growing popularity of bare-knuckle boxing in Poland. As Gromda’s most recognizable champion, he has helped legitimize what many initially viewed as a fringe sport. His technical approach has demonstrated that bare-knuckle boxing can be more than just wild brawling – it can showcase high-level fighting skills.

In Poland, Kubiszyn has become something of a folk hero, particularly in his hometown of Lubaczów and in Rzeszów where he works as a firefighter. His dual identity as both a civil servant and combat sports champion has endeared him to fans who appreciate his humility despite his success.

Kubiszyn’s influence extends to aspiring fighters as well. His success has created a pathway for kickboxers and traditional boxers to transition to bare-knuckle competition. Many young Polish fighters now cite Don Diego as their inspiration for entering combat sports.

As bare-knuckle boxing continues to gain mainstream acceptance globally, Don Diego’s technical approach may serve as a template for future generations of fighters. His legacy will likely be that of a pioneer who helped transform bare-knuckle boxing from a spectacle into a legitimate combat sport with technical depth.

Future Prospects and Challenges

At 33 years old, Don Diego is at a crossroads in his combat sports career. While still in his physical prime, he faces decisions about which direction to take his fighting future. As the reigning Gromda champion with a perfect record, he has essentially conquered the Polish bare-knuckle boxing scene.

One potential path forward is international expansion. Organizations like Bare Knuckle Fighting Championship (BKFC) in the United States have expressed interest in bringing top European talent to their events. A move to BKFC would offer Don Diego the opportunity to test himself against international competition and potentially become a global bare-knuckle boxing star.

Alternatively, Kubiszyn may choose to focus more on his ventures in MMA or kickboxing. Despite his recent loss in FAME MMA, his combat sports versatility gives him options that many specialized fighters lack. With dedicated training in wrestling and Brazilian Jiu-Jitsu, he could potentially develop into a more well-rounded MMA competitor.

The biggest challenge facing Don Diego may be balancing his fighting career with his work as a firefighter and his family responsibilities. Unlike many professional fighters who train full-time, Kubiszyn must divide his time between multiple demanding roles.

Whatever path he chooses, Don Diego’s technical skills, work ethic, and championship mentality suggest that he will continue to be a formidable presence in combat sports for years to come.

Conclusion: The Legacy of Don Diego Gromda

Mateusz „Don Diego” Kubiszyn represents a rare combination of technical excellence, raw courage, and humble character that has made him one of Poland’s most respected combat sports figures. From his beginnings in kickboxing to his current reign as Gromda’s undefeated champion, his journey illustrates the evolution of a true martial artist.

His perfect 10-0 record in bare-knuckle boxing speaks to his dominance in the sport, but perhaps more impressive is the manner in which he has achieved these victories. In a discipline often characterized by wild exchanges and brutal damage, Don Diego has brought a level of technical refinement that has elevated the entire sport.

Beyond his athletic achievements, Kubiszyn’s dual identity as both a champion fighter and a dedicated public servant offers an inspiring example of balance and purpose. His story reminds us that combat sports at their best are not merely about violence but about discipline, respect, and the pursuit of excellence.

As bare-knuckle boxing continues to grow in popularity worldwide, Don Diego’s legacy as one of the sport’s most skilled practitioners is secure. Whether he chooses to expand his horizons internationally or continue his dominance in Poland, his impact on combat sports will be felt for years to come.