When Mirko Filipovic arrived in the Ultimate Fighting Championship at the beginning of 2007, it was the most highly anticipated free agent signing in the history of the promotion. The former K-1 star and Pride Fighting Championships grand prix winner was one of the top heavyweights in the world—and likely the most feared: a lithe, stone-faced striker with blistering hands and a lethal left high kick.

After a perfunctory run through Eddie Sanchez at UFC 67 in February, “Cro Cop” was matched against the 7-1 Gabriel Gonzaga at UFC 70 on April 21, 2007, with a shot at Randy Couture’s heavyweight title explicitly on the line. While many observers seemed to regard the fight as a mere formality—including the sports books, which installed Filipovic as a 6-to-1 favorite—Couture himself, as a guest in the commentary booth that night in Manchester, England, politely offered up his opinion that Gonzaga represented a more difficult matchup.

As it turned out, Couture had some idea of what he was talking about. Once the fight began, “Cro Cop” managed to land exactly one of his trademark kicks before the hulking Brazilian ran him to the canvas. Stuck under a Brazilian jiu-jitsu black belt who outweighed him by 20 pounds, Filipovic did well to survive, but little more, as Gonzaga bloodied him with short punches and elbows from full guard. With just over 30 seconds left, referee Herb Dean stood the two men. While this theoretically put the Croatian back in his element and in position to do something spectacular, precisely the opposite happened. Gonzaga launched a right high kick that landed flush over the ear, knocking Filipovic cold so instantly that he fell in a heap with his own right foot twisted grotesquely under him. It was all over at 4:51 of the first round—one of the most stunning outcomes in MMA history, not just for the result but for the ironic way in which it had occurred.

From there, Gonzaga went on to challenge Couture for the heavyweight crown at UFC 74 in August, as “The Natural” dominated him for two lopsided rounds before ground-and-pounding his way to a TKO win early in the third. Gonzaga, however, remained a Top 10 contender for several years to come.

For his part, “Cro Cop” also remained a contender in the UFC for several years before taking off for Japan, where he had first risen to fame, and experiencing a competitive rebirth. He even returned to kickboxing and won the 2012 K-1 World Grand Prix. When Filipovic retired in 2019 after a fight-related stroke, he was enjoying a 10-bout winning streak in MMA that included a victory in a revenge match with Gonzaga in what turned out to be his final UFC bout.