Hopes for a revival of rugby and unprecedented Olympic status for golf were raised when the International Olympic Committee dropped the US-sponsored sports of softball and baseball - the first sports to be ditched since polo in 1936.
But in a dramatic turn of events that was interpreted as a snub to the intentions of the IOC president, Jacques Rogge, they were not replaced and the number of sports will be reduced in 2012 from 28 to 26.
The secret ballot at the 117th session of the IOC delivered bittersweet news for the London Games organisers. It saves them £50m which would have been spent on temporary stadiums of 5,000 and 15,000 for the softball and baseball in Regent's Park, but the Games will not be host to rugby union or a first Olympic golf event.
Both sports were widely considered as favourites to be included for 2012 and would have handed a significant boost to London. The proposed rugby sevens tournament - the short form of the game preferred to include smaller nations - would probably have been staged at Twickenham or even Wembley and was expected to attract large crowds.
The International Rugby Board said that the IOC had missed a "golden opportunity" to modernise the summer Games and had arrested the game's development in Africa and the Pacific region. The inclusion of golf would have raised the prospect of a British team playing at such courses as St Andrews or, more probably, Wentworth and Royal St George's in Sandwich, Kent.
Both sports would have boosted the Games coffers with improved takings on ticketing, merchandising, licensing and television rights for the IOC. It was estimated that the rugby tournament, which would have been staged the week before the main sports programme started, would have raised £7.5m in ticket receipts alone.
Their exclusion has been interpreted as a second snub in three days for Rogge. Not only was he widely thought to have preferred Paris for the 2012 Games but his love of rugby was well known among the 115 voting members.
Rogge, a former Belgian rugby international who was among the spectators at the recent Twickenham Sevens tournament, wanted his movement to follow the examples of the Commonwealth and Asian Games, which have adopted the sport. It was at the insistence of Rogge that each of the 28 sports had to justify their existence with a vote on their popularity at the Singapore meeting.
Golf is thought not to have found favour because it was perceived in the IOC as an élitist, rich man's sport with little expectation of the world's top players attending in 2012.
A complicated ballot procedure saw squash and karate shortlisted from a list of five applicant sports, with roller hockey also vying for inclusion. It is thought that karate, which is hugely popular around the world, was rejected because the Games already has two martial arts in taekwondo and judo.
The vote prompted theories that a deal had been done between powerbrokers within the IOC to cut the number of sports by two so that each received a larger share of the television revenues. Television income from Athens of £138m was distributed among the 28 federations from the Athens Games and revenues are expected to be higher for Beijing and London.
The outcome of the vote has upset the gender balance by dropping softball, which is only a women's team sport at Olympic level. Baseball is thought to have been sacrificed as an Olympic event because it did not attract Major League players from the US and the sport has been mired in scandal over performance-enhancing drugs.
The London 2012 communications director, Mike Lee, said: " We are delighted to be delivering the Olympic and Paralympic Games in 2012 whatever the size of the sports programme."Reuse content