Dozens of Turkish journalists began cheering and congratulating each other in the media centre outside the hotel where the vote was taking place, only to realise they had got it wrong.
The mix-up happened after the first of two rounds of voting between the three candidates, Tokyo, Istanbul and Madrid.
Tokyo received 42 votes in the first round, the highest of the three candidates, but not enough for an absolute majority to secure the Games.
Under the IOC's regulations, a second round was needed, with the city receiving the lowest number eliminated from the extra ballot.
But when Istanbul and Madrid both received 26 votes, an extra vote was required to split them, which led to the misunderstanding.
When the IOC president Jacques Rogge announced that Istanbul had won the vote, the Turkish supporters erupted in celebration, waving flags and chanting 'Istanbul', thinking they had been awarded the Games instead of the right to join Tokyo in the final round.
Their confusion was not helped by a series of power failures at the media centre that were caused by an electrical storm in the Argentine capital.
The audio and visual broadcasts of parts of the final bid presentations dropped out when the live feed broke and hundreds of reporters were unable to work when their internet connections failed. Water even began leaking through the roof, flooding parts of the room.
The premature celebrations revived memories of the epic misunderstanding during the award ceremony for the 2000 Games, when millions of Chinese thought Beijing had won the bid.
The then-IOC President Juan Antonio Samaranch paused before announcing the winning city to thank each of the candidates, naming them in alphabetical order.
When Beijing was the first name read out, celebrations erupted in China, with people dancing in the streets and letting off fireworks, before they eventually realised Sydney had won.
- Politics & Government