"They are a superior and boastful people," said Adrian Boas, a Brazilian, of the Argentines.
"Forgive the discourtesy but I believe that that is because there are English roots to their culture. They are uncontrollable when they come here, too. They drive their cars so fast that our police cannot stop them."
These insults have been raining in for days. The Brazilian media characterises the fight in straightforward terms - Messi v Neymar, Maradona v Pele - though it is actually far more complicated and interesting than that. The Brazilians might consider the Argentines to have all the qualities of a wasp but Alex Bellos, author of Futebol, subscribes to the view that Brazilians are not all that interested in that nation. They look to Miami and Paris, rather than Buenos Aires. Argentina have a narrower perspective. They just want to put one over on their neighbours.
The picture is even more complicated here in the southerly Rio Grande do Sul, which in some ways is Argentinian by any other name.
The region shares with Argentina and Uruguay some of the same vast grasslands which gave birth to the gaucho cowboy.
The gaucho, most commonly associated with Argentina, is the local symbol, just like theirs. The players of this colder, harsher corner of the vast Brazilian nation are even known as "gaucho" players - Ronaldinho was Ronaldinho Gaucho when he played at Gremio. Brazilians love a gaucho in their team because it is thought they are tougher, run harder and with more heart and passion than those from the heart of Brazil.
Messi creates another layer of complication. Brazilians just can't abhor him like they did Maradona, because they feel he has a touch of Brazilian about him.
But the subtleties tend to get cast aside in a World Cup. Neither nation has grounds for supreme confidence because both remain heavily dependent on their single star commodity.
The arguments will run and run until one of the teams drops away from this tournament, or else the two collide in the Maracana on July 13. For now, the Argentines are making the most of what is their most emphatic annexation since Goose Green.
The World Cup-winning teams from 1978 and 1986 were also expected in the stadium here today, having joined in the mass exodus.