Jamaica look set to claim another two sprint gold medals tonight, with the double champion Usain Bolt to run in the men's 4 X 100 relay final after the three countries that won medals in Athens were all disqualified.
Dropped batons eliminated the United States men and women in Beijing as well as the 2004 men's bronze medallists Nigeria, while the defending men's champions Great Britain were disqualified for an illegal baton change.
Jamaica completed a clean sweep of individual sprint golds with Veronica Campbell-Brown winning the 200 metres from the American world champion Allyson Felix and Jamaica's 100 metre silver medallist Kerron Stewart third.
The Americans also lost the final of the women's softball event, the first time that's happened since the sport made the Games in 1996.
But they did win the women's football final, defeating Brazil 1-0 in extra time for their third gold in four Games.
The USA has won a major sprint medal at every Games since 1984 and this year's collection of silvers and bronzes will be little consolation.
There was some solace in the men's 400 metres however. LaShawn Merritt beat the defending champion Jeremy Wariner to deliver the Americans' seventh straight gold in that event.
But that will do little to chip at the dominance of China in the medals table where the hosts have 46 golds to the USA's 29.
