22-year-old the first athlete to complete 100m, 200m double since Carl Lewis.
Jamaica's Usain Bolt broke the 200-meter world record Wednesday to complete the first Olympic golden sprint double in 24 years and the first 100-200 twin triumphs to feature two world records.
Just four days after shattering his own world 100m record, and on the eve of his 22nd birthday, Bolt pulled away around the curve and won in 19.30 seconds.
"I have a great feeling. It's a dream come true," Bolt said. "I got out good. I ran the corner as hard as possible and once I entered the straight I told myself to keep it up - 'Don't die on me now.'"
Bolt, who had not before been pressed to run to the finish line at these Games, raced past the former world record of 19.32 set by American legend Michael Johnson at the 1996 Atlanta Olympics.
"I left everything on the track," Bolt said. "I'm shocked. I have been aspiring to the world record for so long. I never expected this. I knew the track was a fast track, but I didn't think this was possible."
Not since Carl Lewis in 1984 had any man claimed 100m and 200m gold in the same Olympics, but this lightning Bolt struck twice in the same place to the delight of 91,000 roaring fans at the Bird's Nest.
"I was worried but I told myself to leave everything on the track," Bolt said. "I had come here to do it and I'm so happy with myself."
Bolt completed his quest to become the ninth man to achieve the 100-200 Olympic double after winning the 100 final on Saturday in an astounding 9.69 seconds, breaking his former world mark of 9.72 from May in New York.
Still, Bolt said he will cherish he 200 medal more than his 100 gold.
"The 200 medal, it has been my dream," Bolt said.
"I worked so hard to become the champion and I will work harder to stay on top."
As Bolt danced around the track on a victory lap, the stadium loudspeakers played "Happy Birthday" to the Jamaican some 90 minutes early.
After crossing the finish line and raising his arms in celebration, Bolt grabbed a Jamaican flag and draped it around his neck. He took off his golden shoes and began an impromptu celebration dance.
Churandy Martina of Dutch Antilles crossed the line a distant second to Bolt in 19.82 with Wallace Spearmon next but both were later disqualified by officials.
The US team appealed Spearmon's penalty, withdrew that, protested Martina for running outside his lane and had that protest upheld, leaving 2004 Olympic champion Shawn Crawford second in 19.96 and fellow American Walter Dix third in 19.98.
The whole mess only stretched Bolt's victory margin even more than the man did himself.
Crawford could only marvel at Bolt, who reminded him of US eight-gold swim superman Michael Phelps.
"The guy came out and made the best Olympics of my lifetime," Crawford said. "To me, Bolt is like what Michael Phelps is to swimming."
Ironically, Johnson had said just hours earlier he did not think Bolt had what it took to erase his record from the books in Beijing.
"I don't think his training has been geared to that part yet," Johnson said. "But in a few years it will be and then I will be ready to kiss my record goodbye."
Bolt was not the only Jamaican to mine gold.
Melaine Walker continued the island's domination of US women by winning the women's 400m hurdles in 52.64 seconds with American Sheena Tosta second in 53.70 and Britain's Tasha Danvers third in 53.84.
The grudge match began when Jamaicans swept the women's 100m medals with three Americans adrift and will continue in Thursday's women's 200m finals.
World champion Allyson Felix of the United States and 2004 Olympic champion Veronica Campbell-Brown of Jamaica led trios of women from their nations through the 200m semi-finals.
Campbell-Brown won her semi-final in 22.19 seconds. Felix answered by winning her heat in 22.33.
World record-holder Dayron Robles of Cuba booked his place in Thursday's 110m hurdles final by winning his semi-final in 13.12 seconds.
Reigning 1,500m and 5,000m world champion Bernard Lagat bounced back in the opening heats of the 5,000m after failing to reach the 1,500m finals, the American winning his qualifying heat for Saturday's final in 13:39.70.
Olympic 1,500m champion Kenenisa Bekele of Ethiopia continued his bid for a distance double by finishing third in Lagat's heat.
World pole vault champion Brad Walker missed three attempts at 5.65m, the American posting no height to miss out on Friday's final.
Aksana Miankova of Belarus won the women's hammer throw with a best effort of 76.34m.