World record holder Ashton Eaton of the United States won gold in the decathlon, while American teammate Trey Hardee picked up the silver.
Eaton led from start to finish, earning first-place finishes in the first two disciplines -- the 100 meters and long jump -- and holding onto his advantage through the remainder of the grueling two-day, 10-event competition.
He finished with 8,869 points, 198 more than Hardee and only 24 points behind the Olympic record set by Roman Sebrle of the Czech Republic at the 2004 Athens Games. Cuba's Leonel Suarez claimed bronze and was 346 points behind Eaton.
This is the second straight decathlon gold for the U.S. after Bryan Clay won the event four years ago in Beijing. This marks the first time Americans have placed 1-2 in the event since 1956, when Milt Campbell won gold and Rafer Johnson placed second.
Eaton built up a 222-point lead over Hardee by the end of Thursday's day session and had to do very little to complete gold on the second night of the competition.
The 24-year-old Eaton placed ninth in the javelin competition and eased his way to a time of 4 minutes, 33.59 seconds in the 1,500 meters.
"I'm young and it's super hard to grasp but when I'm older I'll look back at this," Eaton said.
Along the way to his first Olympic title, Eaton set a new decathlon mark in the 100 meters, running the sprint in 10.35 seconds. He placed first in three disciplines and second in two more.
"I want 10 perfect events," Eaton declafed. "I know that's pretty much impossible but that's the decathlon. I'd need that to be considered the world's greatest all-round athlete."
Eaton broke the decathlon world record with a score of 9,039 at U.S. trials this year. He and Sebrle are the only two men to break the 9,000-point barrier. The 37-year-old Sebrle started the competition in London, but bowed out after a poor showing in the 100 meters.