Jamaica's Veronica Campbell-Brown has become the first women to defend her 200m crown in 28 years, while LaShawn Merritt salvaged some pride for the Americans in the men's 400m.
Following victories in the 100 and 200m for Usain Bolt, a 1-2-3 in the women's 100m and gold in the 400m hurdles for Melaine Walker, Campbell-Brown powered to victory in the Bird's Nest Stadium in a new personal best of 21.74 seconds to complete a Jamaican clean sweep of the men's and women's 100m and 200m sprint events
Athens runner-up Allyson Felix of America again had to settle for silver in 21.93secs with another Jamaican, Kerron Stewart, claiming the bronze.
Later, Merritt upset compatriot Jeremy Wariner in the 400m as the USA finished 1-2-3 with David Neville third.
Wariner, as the defending champion, was expected to dominate, but Merritt ran a brilliant final bend to cruise up to him and win in 43.75 seconds, over a second clear of the world and Olympic champion.
Earlier, it had all turned very bad for the Americans in the relay heats with both their men's and women's 4 x 100m team disqualified.
The American men's quartet were set for a comfortable qualification until Darvis Patton and world champion Tyson Gay botched the final changeover, the baton dropping to the track as Trinidad and Tobago went on to win the heat in 38.26 seconds.
Gay, who failed to qualify for the individual 100m final after his build-up was ruined by a hamstring injury, said: "The stick was in my hand but when I went to grab it he had already let go. It takes a second to feel it."
"It is probably my fault. I am going to take the blame for it. I have never dropped a stick in my life. It is just the way it has been happening for me this year."
There was more misery for the United States in the women's relay when they again dropped the baton on the final changeover, Torri Edwards and Lauryn Williams this time the guilty duo.
Belgium won the first semi-final in 42.92 seconds ahead of the British quartet Jeanette Kwakye, Montell Douglas, Emily Freeman and Emma Ania.
Jamaica cruised to victory in the second semi-final with Campbell-Brown running the anchor leg 90 minutes after successfully defending her 200 metres title.
Barbora Spotakova of the Czech Republic snatched gold in the javelin with the penultimate throw of the competition, a personal best of 71.42m taking her ahead of long-time leader Maria Abakumova of Russia. Christina Obergfoll of Germany took bronze.
In the men's 110m hurdles final, Cuban Dayron Robles produced the goods. The world record holder clocked a time of 12.93, 0.06 outside his best, but he easily defeated American pair David Payne and David Oliver.
The men's triple jump was extremely close with just 15cm between the top four. Gold went to Portugal's Nelson Evora with an effort of 17.67m, while Britain's Phillips Idowu (17.62) took silver and Leevan Sands of the Bahamas (17.59) was third.
Kenya's Nancy Langat was the fastest qualifier in 4:03.02 for Saturday's women's 1500m final, while there was a major shock in the men's 800m as defending champion Yuriy Borzakovskiy failed to qualify for the final.
With just the first two in each semi-final going through by right, the Russian could only finish third in the opening race and also missed out on a spot as one of the two fastest losers. World champion Alfred Yego of Kenya was the fastest qualifier in 1:44.73.