Norifumi Yamamoto once ended a professional MMA fight in just four seconds flat.

Countries & Cities · Published 15 October 2026 Swipe more like this →

In short: Known as Kid, Norifumi Yamamoto was a Japanese martial arts icon whose career spanned wrestling, kickboxing, and the UFC. He famously secured the fastest knockout in a major MMA promotion with a flying knee, yet his path was marked by both legendary winning streaks and persistent, career-altering physical injuries.

Born into a wrestling dynasty, Yamamoto’s father, Ikuei, competed in the 1972 Munich Olympics, and his sisters were world-class freestyle wrestlers. After training in Arizona, Yamamoto transitioned to mixed martial arts at age 21. His professional debut in 2001 launched a career defined by an aggressive, versatile style that brought him massive popularity in the Shooto and K-1 Hero's organizations. By 2005, he had cemented his status by winning the K-1 Hero's Middleweight Grand Prix.

Yamamoto’s athleticism was perhaps best captured on May 3, 2006, when he knocked out Kazuyuki Miyata with a flying knee just four seconds into their match. This remains one of the most iconic moments in MMA history. However, his career was frequently interrupted by severe injuries. A dislocated elbow in 2007 ended his dream of following his father to the Olympic Games, and subsequent knee and training injuries forced him to withdraw from multiple high-profile UFC bouts throughout the 2010s.

Despite his early dominance—including a 14-fight winning streak—Yamamoto struggled to replicate his success in the UFC, where he went winless across four appearances. His final years were marked by a private battle with stomach cancer, which he was diagnosed with in 2016. He kept his condition hidden from the public until August 2018, passing away shortly thereafter in September 2018. His legacy remains that of a trailblazing fighter who bridged the gap between traditional wrestling roots and the explosive evolution of modern mixed martial arts.

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