Shawn Crawford led home a USA 1-2-3 in the men's 200m final to a chorus of boos in the Olympic Stadium.
Crawford ran 19.79 seconds, the eighth fastest time in history, to finish two metres clear of Bernard Williams.
100m champion Justin Gatlin faded to third, with 36-year-old Frankie Fredericks fourth in his final race.
The start of the race was delayed by eight minutes as the Greek crowd voiced their protest at the absence of disgraced champion Kostas Kenteris.
Crawford insisted that the hostile reception had not affected him in any way.
"It wasn't difficult at all," he said.
"It was part of our game-plan - my coach warned us that they (the crowd) would not let us start.
"It's part of being a champion - you have to be ready to focus once the gun goes."
Catcalls and whistles
Crawford was slow out of his blocks but powered round the bend to lead Williams by a fraction as they entered the final 100m.
Williams celebrates silver
He then accelerated away in style to wipe away the disappointment of finishing fourth in the 100m final four nights before.
The stadium had rung to catcalls and whistles as the finalists went to their blocks, and the crowd continued to shout, "Hellas, Hellas," when asked for silence.
The crowd appeared to be voicing their own protest at the treatment of former Greek hero Kenteris, who was excluded from the Games after missing a drugs test.
Crawford's gold was the first major outdoor success of a career that has too often put mirth before medals.
He was formerly best known in his home country for racing a zebra and giraffe on Fox television.
After beating the latter but being outsprinted by the former, he demanded a
rematch, accusing the zebra of a false start.
Then there was the time two years ago when he wore a Phantom of the Opera-style mask in a race in Italy.
The mask slipped mid-race, Crawford ran out of his lane and then found himself disqualified.
Both Crawford and Gatlin are coached by Trevor Graham, the same man who coached 100m world record holder Tim Montgomery and his girlfriend, former Olympic 100m champion Marion Jones.
Graham was the man who set off the Balco drugs scandal by sending a syringe containing previously undetectable steroid THG to the US Anti-Doping Agency, allowing them to devise a test for the drug.
On Wednesday, Britain's Christian Malcolm and Darren Campbell had both gone out of the 200m at the semi-final stage in disappointing fashion.
Malcolm came home seventh in his semi in 20.77 seconds, way outside his best, while Campbell trailed in eighth and last in the first semi.