Brazil may have waltzed through their group to reach the semi-finals of the Confederations Cup but they are only too aware of the party pooping abilities of tomorrow's rivals' Uruguay.
It was the Uruguayans who delivered Brazilian football its arguably greatest ever blow in winning the 1950 final in Rio's famed Maracana stadium, the revamped version of which will host Sunday's final where either world champions Spain or Italy await.
That 'Maracanazo' loss sent shockwaves around Brazil and they only made up for the reverse eight years later when, with a teenaged Pele in the team, they finally lifted the trophy for the first time in Sweden.
More recently, Uruguay have also shown they can mix it with their more powerful neighbours, the nation of barely 3.5 million lifting the 2011 Copa America in Argentina, where Brazil lost in the quarter-finals to Paraguay.
Brazil goalkeeper Julio Cesar yesterday warned the host nation they must beware if they are not to suffer an ambush in Belo Horizonte, a venue which earned its own place in World Cup folklore in the 1950 event by hosting a United States win over England.
Uruguay have shown some mediocre recent form in World Cup qualifying but the 2011 South American champions have found some form with wins in Brazil over Nigeria and thrashing minnows Tahiti.
Moreover, Julio Cesar points out that in Edinson Cavani, Diego Forlan - match winner against Nigeria with a record 34th goal for the Celeste - and Luis Suarez the Uruguayans have no shortage of firepower.
"They are very strong in attack and can decide a game on their own," the shot-stopper said.
The trio are set to return after being rested for the 8-0 whipping of Tahiti.
"I know them all well and we shall have to beware. The tiniest thing can decide a match," added Cesar, who faces the prospect of playing second tier English football next season after being relegated with Queens Park Rangers.
Brazil, starting to come to the boil under 2002 World Cup handler Luiz Felipe Scolari, saw off Japan, Mexico and Italy but Uruguay had to regroup after losing their first match against world champions Spain, who will face Italy in the other semi-final.
"Nobody is favourite. They will be confident as they won the Copa America in 2011," said Julio Cesar.
The four semi-finalists have won 12 World Cups between them - a record five for Brazil, four for Italy, two for the Uruguayans and one for Spain.
Uruguay last beat the Selecao in 2001 - ironically it was Luiz Felipe Scolari's first match in charge, but Big Phil would months later lift the World Cup to land a Pentacampeao or fifth title.
Since then the record book reads four wins for the auriverde and two draws.
Brazil were booed off here after a friendly draw against Chile in the run-up to the Confederations event, but midfielder and local boy Bernard says this is totally different.
"That was a friendly and we were just putting the group together. But now we have a solid platforn with three straight wins under our belts."
Belo Horizonte, Brazil's third-largest city and the capital of the state of Minas Gerais, has seen two bouts of the social unrest which has swept Brazil in the past fortnight.
Last week, 20,000 took to the streets to protest at the cost of staging the event and the World Cup when the country is struggling to overhaul crumbling public services.
Then, last Saturday, 70,000 people turned out to protest in the city centre, with 25 people hurt and a similar number arrested.
Uruguay's wily coach Oscar Tabarez says his team has "reached its minimum objective" in making it out of the group stage and while he accepts Brazil are probably favourites, he sticks to an old optimist's dictum.
"In football, nothing is imposible. Though it will be tough as Brazil are a great team and playing at home."