The cheers, shouting, hugs and applause soon blended into a carnival-style celebration complete with the sound of samba and silver ticker tape.
The beers - and the even more potent caipirinhas - were soon flowing.
A short time earlier there was a sense that things were moving Rio's way with the shock early exit of Chicago.
Many of the waiting crowd were as incredulous as people in other parts of the world, and Madrid became the focus of new and nervous attention.
However, convinced by the Rio bid's cheer leader in chief, President Luiz Inacio Lula da Silva, many people here had come to believe that South America's time had come.
Brazilians are passionate about sport and about their country, and this was good news on both fronts.
AT THE SCENE
Paulo Cabral, BBC Brasil, Deodoro
Rio's victory was received with mixed feelings in the poor and run-down neighbourhood of Deodoro, the second most important site for the 2016 Olympics due to the area's many military sporting facilities.
But even in the bars where TV sets were tuned to channels showing the Copenhagen decision, not everybody was paying attention.
Unemployed Davidson Costa da Silva complained the government had the wrong priorities.
"I don't think this is what we should spend money on now," he said. "Look at our hospitals and our schools and you will know what I mean."
Undoubtedly in some of Rio's poorest areas there are those who doubt, with the benefit of bitter experience, whether the benefits of this sporting pageant will come their way.
But others are hopeful that the Olympics will help to revitalise the city to tackle some of its deeply rooted social problems.
"I think Rio is showing its face to the world," Fabiano Mexas, 34, told the BBC News website.
"Brazil is always criticised for its poverty and violence, and this is the chance to show that we are also part of the first world."
Paloma Cannuti, 22, said: "I think it is going to change security and transportation.
"The metro is improving, the trains and the buses, and it is going to be much more integrated, until we link up with the Olympic village."
With most of his bosses in Copenhagen, Rio's tourism secretary, Antonio Pedro Figueira de Mello was jubilant about the city's success and keen to dismiss any doubts.
I confess to you if I die right now my life would have been worth it
"This changes everything and changes the story of Rio," he said. "It is a moment that we fought for over a long period. It is a radical change in terms of transport, in terms of the logistics and infrastructure of the city.
"'We did our homework' as you say in English, and showed we had the capacity to stage the games here - the first games in South America.
"I don't have any doubt that the violence in Rio will not be a problem. We don't have terrorist attacks here, we don't have those huge problems here.
"We have been able to able to stage major events - Eco in 1992 was here, the Rolling Stones concert, the Pan-American games, we are going to have the World Cup in 2014, the military games in 2011.
"So Rio de Janeiro is prepared, it has shown this in the past and it is going to demonstrate again with clarity for the world in 2016 that Rio is the Olympics city."
The former Brazilian gymnast Luisa Parente had no doubt that the money spent would be well worth it and would particularly benefit young people.
A promotional video which aims to boost Rio's bid - copyright IOC 2009
"These games will bring pride to them, they will be proud to be at this time living here and being part here - even if they aren't at the games," she said.
"As a former gymnast I have been in two Olympic games, and as an athlete I felt very proud to be there and my family and country were proud. "Now 'there' will be 'here' and I can't imagine how proud we will be!"
There have been question marks in the past about unfulfilled pledges made by the Brazilian authorities in relation to major sporting events - but the authorities here insist that this time promised improvements will be delivered.
Struggles with inequality
Brazil will be relying on a strong economy that was one of the first to emerge from the economic crisis to provide much of the budget for the Olympics.
The decision also seems to mark a defining moment for South America's largest country, which despite its struggles with inequality, poverty and violence is carving out a new leadership role for itself in the developing world.
While there has been much comment on the setback Chicago's early exit represented for President Obama, Rio's triumph was also a personal victory for Brazil's President Lula.
He threw his considerable personal charisma behind the bid, never losing an opportunity to declare that while for other countries this was just another Olympics, Brazil needed the games.
This focus on the inclusivity of the Olympic message and the importance of a lasting social legacy clearly had a resonance for those who made the decision over the 2016 games.
President Lula appears to have studied the way former UK Prime Minister Tony Blair helped secure the Olympics for London, and skilfully adopted the approach for his needs.
Brazil will now host the World Cup in 2014 and the Olympics two years later, which even for a nation that has had so many sporting landmarks in its history will surely be a remarkable period.
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