Grenal is the nickname for matches between two of Brazil's leading football clubs, both located in the city of Porto Alegre, state of Rio Grande do Sul, the southernmost state in Brazil: Gre refers to Grêmio Foot-Ball Porto Alegrense and Nal refers to Sport Club Internacional.
The grenal is one of the fiercest football rivalries in South America. It is accompanied by high levels of emotion, competition and occasional violence. Many well-known players have competed in grenal games, including: Everaldo, Tesourinha, Aírton, Falcão, Éder, Valdomiro, Renato Gaúcho, Taffarel, Dunga, Emerson, Ronaldinho, Elías Figueroa, Nilmar, Oscar, Abbondanzieri and Diego Forlán.
The game has also seen world-famous coaches such as Luiz Felipe Scolari, Abel Braga, Carlos Alberto Parreira, Telê Santana, Rubens Minelli, Valdir Espinosa, Paulo César Carpegiani and Ênio Andrade manage a game.