After beating Paraguay 4-1 on Sunday, Brazil spent three days in paradise.
Or rather, three days and three minutes, until Hernan Crespo's goal dampened a nation's celebrations and set Argentina on the way to a 3-1 victory and a place in the 2006 World Cup.
Brazil's newspapers had been dominated by a single thought this week: finally they had a national team with the magic to match the class of 1970.
The brilliant quartet of Ronaldinho, Robinho, Kaka and Adriano had sent Paraguay packing in style. Could they do the same against Argentina?
It did not take long to find out.
Brazil coach Carlos Alberto Parreira, like most in his trade, is obsessed with the concept of balance, finding an equilibrium between attack and defence.
His team's defeat will surely remind him of an old saying in Brazilian football: trying to balance a side is like having a small blanket on a cold night - cover your neck and your feet get cold, cover your feet and your neck freezes.
Wednesday was a very cold night in Buenos Aires.
It was an exhibition and Riquelme had the freedom of the park
Parreira, with his two strikers and two attacking midfielders, pulled the blanket up as high as it would go - and found that it left his side dangerously exposed.
Argentina may not be able to boast the breathtaking individual talent of Brazil, but in attack and defence they played collectively.
Brazil's stars frequently found two markers snapping at their heels and, after they had won possession, Argentina showed that they can pass the ball better than any other side in the world.
With playmaker Juan Roman Riquelme pulling the strings, they passed through holes in the Brazilian team throughout the first half.
Quick, four-man combinations, delightful moves starting on the left and finishing on the right - it was an exhibition and Riquelme had the freedom of the park.
The Brazilians were outplayed and outthought in Buenos Aires
Together with his gifted lieutenant Lucho Gonzalez, he played the ball around, through and above Brazil's overworked defensive midfielders.
As befits a proud side, Brazil came back in the second half. As Argentina dropped deeper they at last found the space to set their moves in motion.
Their best spell came in the last 30 minutes, after Parreira had given up on the magic quartet. Robinho was replaced by Renato, an extra marking midfielder, and Riquelme disappeared from the game.
Lucho Gonzalez came off and suddenly the pressure was all coming from Brazil.
They pulled one back, and were unlucky not to get a second - but the damage had been done. It was too much to expect that they could give Argentina a three-goal headstart and still come back.
Argentina, then, have qualified. Brazil are not far behind, and should seal qualification in the next round.
They will go to Germany perhaps stronger for the fact that Argentina punctured their balloon of euphoria.