Nieky “The Natural” Holzken built a two-decade career as one of kickboxing’s most feared finishers, compiling nearly 50 knockouts in kickboxing and another 11 in professional boxing en route to multiple world titles. From a career-defining uppercut to a spinning back kick landed at age 41, here are the finishes that best capture why opponents feared stepping into the ring with him.
The Uppercut That Announced His ONE Championship Arrival
Holzken’s debut in ONE Super Series remains one of the signature moments of his career. On November 17, 2018, at Stadium Istora in Jakarta, Holzken knocked out three-time kickboxing world champion Cosmo Alexandre with a crushing uppercut, sealing the win in the final second of round two of their 78-kilogram catch weight bout. The finish carried extra weight given their history. The pair had first fought back in May 2010, with Holzken winning by decision, and this knockout victory came more than eight years later as a far more emphatic statement. Holzken celebrated by miming putting on a championship belt, signaling his intention to chase a ONE World Title.
Avenging a Loss With a Spinning Back Kick at 41
Even deep into his career, Holzken proved capable of producing highlight-reel finishes against elite competition. On March 14, 2026, at ONE Friday Fights 100, a 41-year-old Holzken avenged an earlier loss to Sinsamut Klinmee with a stunning first-round knockout at 1:58 via spinning back kick under kickboxing rules, evening their rivalry and reaffirming that his striking remained genuinely elite even at an advanced stage of his career. The finish stood out precisely because it came against the backdrop of ONE Championship’s demanding international schedule, which requires frequent travel and strict weight management even for veteran fighters.
A Grand Prix Tournament Run in Superkombat
Holzken’s power wasn’t limited to single-bout knockouts—he also demonstrated it across an entire night of fighting. In 2010, he won the Superkombat World Grand Prix, defeating multiple opponents in a single-night tournament format to claim the title, a performance that showcased both his knockout power and his stamina under high-pressure, back-to-back-fight conditions.
Precision Finishes Against Regional Competition
Beyond his headline bouts, Holzken built his knockout reputation through consistent, efficient finishes across smaller promotions as well. Between 2014 and 2016, competing in Superkombat and Fight Night Rotterdam events, he recorded a notable first-round knockout of Azerbaijani fighter Bahram Aliyev in 2015, a finish that highlighted the precision he brought to closing out fights quickly.
Overpowering a Muay Thai Legend
Holzken’s kicking game proved just as dangerous as his hands against elite Muay Thai competition. In a widely referenced performance against Muay Thai legend John Wayne Parr, Holzken’s kicks were so effective that Parr appeared entirely outmatched, unable to keep pace in the exchange. That performance, alongside standout wins over Cosmo Alexandre and former champion Regian Eersel, is frequently cited among fans as evidence of how thoroughly Holzken could blend boxing-based hand speed with kickboxing’s wider striking arsenal.
A Complete Striking Arsenal
What made Holzken’s knockouts so consistently dangerous across two decades was the sheer range of tools he brought into the ring. Rather than relying on a single dominant weapon, his fights showcased sledgehammer punching power delivered with genuine bad intentions behind every strike, a trait that stemmed directly from his dual background training in both boxing and kickboxing under legendary coach Ramon Dekkers. That combination of hand speed borrowed from boxing and the wider kicking and clinch tools of kickboxing and Muay Thai gave him more finishing routes than most pure strikers in either discipline.
Join The Discussion
Which Nieky Holzken knockout stands out most to you—the emphatic uppercut over Cosmo Alexandre, the late-career spinning back kick against Sinsamut Klinmee, or one of his lesser-known regional finishes? What do you think set his striking apart from other elite kickboxers of his generation? Share your favorite Holzken moments, memories from watching his career, or questions below.
