On 21 May 2011 two teams suffering terrible rins of form met in the 15th round of the Clausura 2011 tournament in Argentina. The hosts Huracán had slipped into the automatic relegation places after a run of five consecutive defeats and the visitors, defending champions Estudiantes had gone 12 games without a victory. After a dreadful goalkeeping error from Pedro Monzón and a free header from hernán Rodrigo López had gifted Estudiantes a 0-2 lead within half an hour the Huracán fans started a riot and succeeded in getting the game abandoned.
Most Argentine commentators seem to agree that Huracán should be severely punished in order to demonstrate that violence will not be tolerated.
For more crazy South American football check out the rest of the Cosas locas series.