On 22 October 1951 after a disagreement with the French rugby union the club switched codes and under the name Sporting Club Limoux XIII they entered the amateur Federal League. In the 1955–56 season they won the cup and were runners-up in the league. In 1962 the club entered the National League and after reaching the cup semi-final in 1967 they lifted the championship title in 1968 in Toulouse against AS Carcassonne, 13–12, after extra time in front of 15,000 fans. The team that day was: Andrieu, Blair, Bonnafous, Belli, Bellinguier, Bernadoi, Costeseque, Datta, Dumas, Guiraud (captain), Lecinena, Marty, Dolly, Parpaiola, Roldos, Satge, and Vergeysnt. Datta, Blair and Guiraud would go on and play against the Australia national rugby league team in the 1968 Rugby League World Cup in what was in effect the final. The win didn't bring in a spell of silverware, as the club wouldn't reach another final until 1984.