On 18 September 1920, Uruguay defeated Brazil 6-0 in the South American Championship, a beating that remains Brazil's worst-ever loss.
The margin of victory was surprising, but the two sides had a history in the tournament. Uruguay had won the first two competitions, in 1916 and 1917, but Brazil claimed the honors in the third tournament, played in 1919, after beating Uruguay in a title-deciding playoff that went into four extra periods to determine a winner.
In the 1920 edition, Brazil managed a 1-0 win over Chile and Uruguay drew 1-1 with Argentina before the two previous cup winners met each other. Uruguay left no doubt about their intentions to reclaim the title, scoring three goals in a span of seven minutes. Inside forward Ángel Romano scored first, putting Uruguay ahead in the 23rd minute. Antonio Urdinarán (26', pen.) and José Pérez (29') quickly added two more.
The Brazilians were completely undone, as Uruguay scored three more times in the second half (Antonio Campolo - 48', Romano - 60', and Pérez - 65'). Brazil then concluded the tournament with a 2-0 loss to Argentina, while Uruguay proceeded to lift the cup with a 2-1 win over hosts Chile.