The Brazilians defeated Iran 7-1 at the Newton de Faria Stadium on Sunday night.
Iran, coached by Hossein Shams, qualified for the final after playing out a thriller that finished 4-4 after extra time but the nine-time Asian champions prevailed 4-1 on penalties.
Romania managed to come third in the event by beating the Czech Republic 4-2.
A total of 16 teams took part in the international event which kicked off in Rio de Janeiro, Brazil, on June 28.
Last year, the Iranian squad finished as the runner-up in the 2008 Grand Prix de Futsal after it was defeated by the hosts Brazil.
The Grand Prix de Futsal, also known as Futsal Mini-World Cup, is an international futsal competition of the same kind of the FIFA Futsal World Championship but with invited nations and held annually in Brazil. It was first held in 2005.