The rivalry between Flamengo and Atlético Mineiro is a footballing rivalry played between Brazilian clubs Clube de Regatas do Flamengo, from Rio de Janeiro, and Clube Atlético Mineiro, from Belo Horizonte. The clubs first played against each other in 1929, but until regular competitions were introduced in Brazilian football in 1959, the encounters were played at friendly level, since they come from different states: Flamengo is from Rio de Janeiro, while Atlético Mineiro hails from Minas Gerais. The rivalry developed in the 1980s from numerous controversial encounters between the two clubs in that decade's Brasileirão and Copa Libertadores editions. It remained through the following years, and is considered the biggest interstate rivalry in Brazilian football.