The Rosarian derby (clásico Rosarino) is the most important derby between clubs that are not based in the autonomous city or the province of Buenos Aires. It is contested between Newell's Old Boys and Rosario Central, the two major teams in the city of Rosario. The teams nicknames relate from the same incident where Rosario Central refused to play a charity game for a Leprosy charity, hence their nickname Canallas (Scoundrels). Newell's Old Boys stepped in to play the game and earned the nickname Los Leprosos (The Lepers).
Read more about this topic: Football Rivalries In Argentina