On July 4th, 2021, Leon toed the line at his first full distance Ironman event in wet and cold Bolton, UK. This was a first test to see whether or not Leon could be competitive over this distance, which involves 8 hours or more of racing. On a tough course and in harsh conditions, Leon crossed the line in 3rd position, securing his first professional podium and qualifying for the Ironman World Championships 2021.