(CNN) -- The under-performing United States track and field team suffered further humiliation on Thursday as both their sprint relay squads exited the Olympics after blunders on the final changeovers.
Gay and Patton (center) cut forlorn figures after their men's 4x100m relay setback.
The men were the first to suffer disappointment when world 100 meters champion Tyson Gay did not receive the baton from Darvis Patton as he set off for the final leg.
Gay will leave Beijing not just empty-handed, but without even running in a final.
"I take full blame for it," Gay told the Associated Press. "I kind of feel I let them down."
There was more woe to follow in the women's heats when the baton was dropped as it moved from Torri Edwards to Lauryn Williams on the final leg. Williams in desperation ran back to pick up the baton, but it was an impossible task as she came in last.
To rub salt into the wound, the all-conquering Jamaican squads won both their heats in the men's and women's races and look set to claim two more golds.
Usain Bolt, who received his Olympic 200 meters gold in the Bird's Nest stadium just before the races, could afford to rest up while his teammates went through to the final.
Their task was also made easier by the exit of reigning men's champions Great Britain, whose last leg runner Craig Pickering set off too early and received the baton outside the permitted marker, leading to a disqualification of the whole team.
Earlier, there was more Olympic glory for Jamaica as Veronica Campbell-Brown easily defended her 200 meters crown.
She routed a below-par Allyson Felix of the United States in 21.74 seconds to win the gold by 0.19 second.
"Bolt set it off. After that, I just think the Jamaican camp went crazy," said Jamaican third-place finisher Kerron Stewart.
There was some consolation for the United States in the men's 400 meters where LaShawn Merritt led a sweep of the medals with a 43.75 seconds clocking.
The 22-year-old shocked defending champion Jeremy Wariner, who had gone into the event as a warm favorite, but was well beaten in second place. David Neville stumbled over the line to nick the bronze off the Bahamas' Christopher Brown.
In the absence of Chinese hero Liu Xiang, who had limped out before the heats, Cuban world record-holder Dayron Robles eased to gold in the men's 110 meters hurdles in 12.93 seconds.
The women's javelin fell to Barbora Spotakova of the Czech Republic who won gold with her final throw.
The world championship gold medalist was in second place but then produced a European record 71.42 meters to beat Maria Abakumova of Russia.
The final gold of a dramatic night of track and field went to Portugal's world champion Nelson Evora who pipped Britain's Phillips Idowu to the triple jump title. Evora produced a 17.67m jump to move ahead of Idowu (17.62m) who had been the favorite going into the competition.
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