There's something called "home field advantage". Brazil national soccer (football) gives that phrase new meaning:
But this World Cup is being played in Brazil. No country has beaten Brazil on its home turf in almost 12 years. Brazil’s last loss at home came in a friendly on Aug. 21, 2002. That game against Paraguay, incidentally, is one the Brazilians may not have been particularly interested in winning. Brazil had won the World Cup in Japan earlier that summer; the Paraguay match was the team’s homecoming. Although Brazil started most of its regulars, by midway through the game it substituted out almost all of its stars.
To a find a loss at home in a match that mattered to Brazil — in a World Cup qualifier, or as part of some other tournament — you have to go back to 1975, when Brazil lost the first leg of the Copa América semifinal to Peru. None of the players on Brazil’s current World Cup roster was alive at the time.