Claes Johanson won 10 Swedish championships between 1911 and 1924 and added the European Championship in 1913. In 1912 he won Olympic gold in the middleweight A division by forfeit. The Russians Martin Klein and Alppo Asikainen had wrestled for 11 hours and 40 minutes in their previous bout and were too exhausted for another encounter. After repeating his success eight years later in Antwerp in the light-heavyweight class, the Paris Games came as a major disappointment for him. After losing against Frenchman and eventual gold medal winner Henry Deglane in the first round of the heavyweight class, he felt that the jury was biased by the protests of the home crowed in favor of Deglane.
“Gota Lejon,” as he was called, won a total of 203 international fights. In 1917 he was one of the founders of Göteburg AK and served as the club’s chairman until 1944. Johanson also held positions in the Swedish Athletic Federation and the Swedish Wrestling Federation. Prior to his first Olympic appearance he worked in a box factory and claimed that carrying and stacking the planks built up his strength. Johanson was later an ad salesman for the Gothenburg Morning Post.