Stephen Thompson finished Charlie Radtke by knockout in the third round. The fight was the last of Thompson's career, closing out his run with a knockout win.
Stephen Thompson closed the book on his fighting career with a third-round knockout of Charlie Radtke, finishing the bout in the final fight of his run.
The win gave the 43-year-old American the send-off he wanted. Known as "Wonderboy," Thompson trains out of Team Upstate Karate and has fought as an orthodox striker throughout his career. His record stands at 17-9-1, and he leaves the sport with a knockout on his final night.
Thompson's last three recorded fights before this one had all gone the other way. He dropped a split decision to Gabriel Bonfim on July 12, 2025, was stopped by Joaquin Buckley with a third-round KO on October 5, 2024, and was submitted by Shavkat Rakhmonov in the second round on December 16, 2023. Finishing Radtke in Round 3 ends that losing run and makes his retirement fight a win by stoppage.
The numbers show why Thompson stayed dangerous late in his career. He lands 4.11 significant strikes per minute at 46 percent accuracy, a combination built on distance control and precise, karate-based timing. He stands six feet tall with a 75-inch reach, or 191 cm. Takedowns were never part of his game: he averages just 0.25 per 15 minutes and has recorded no submission attempts, which made his career a striking showcase from start to finish.
Why it matters
- Thompson walks away on a knockout win rather than on the three-fight losing streak that preceded it.
- His career ends at 17-9-1, with a stand-up style that kept him competitive over a long run at the top level.
- The 43-year-old retires with a finish, rather than a decision or a late stoppage against him.
Radtke, the man on the other side of the cage for Thompson's farewell, suffered the knockout defeat in the third round.
Saturday, November 14, 2026
