Charlton, who was known for his focused and dogged performances, challenged for the World Championship in 1968, and was the runner-up in the final of the World Championship in 1973 and 1975, losing the 1975 world final by just one frame (30–31) to Ray Reardon. However, his 1972, 1973, and 1980 victories in the BBC's "Pot Black" competition, with its one-frame-per-match format, gave him a high-profile with television audiences. He also recorded the first century break (110) on "Pot Black".