Charles Williams retained his International Boxing Federation light heavyweight title Saturday with an 11th-round technical knockout over Frenchman Richard Caramanolis.

The bout ended when the challenger's corner stopped the fight.

Williams, a 26-year-old from Philadelphia, captured the title last October from Bobby Czyz. He improved to 23-4-2 with 15 knockouts. Caramanolis, 30, was seeking to become the first French fighter in nearly 29 years to claim a world title. He fell to 35-3-2.