"We've got the 'world's greatest athlete' now," he said.
Clay finished the 10-discipline competition with 8,791 points, just 100 off Dan O'Brien's American record and a whopping 240 ahead of the silver medalist. It was the most one-sided decathlon triumph since the 1972 Munich Games.
Clay joins the likes of Bruce Jenner and Jim Thorpe as Olympic champions in an event that an American has won 12 times in 22 Olympics but only twice since 1976.
The event no longer grabs the headlines back home. Case in point: Clay's triumph came just minutes before Usain Bolt and Asafa Powell led Jamaica to a world record in the 4x100 relay. When their news conference started, all but a handful of reporters left Clay.
"I hope the Wheaties box and all those types of things happen," he said. "I'd love for this to be a spark for the decathlon and bring it back to the forefront of track and field."
Clay took the lead from the start, then widened it through most of the second day in a triumph his opponents could only admire. He was no worse than third in seven of the disciplines, including an Olympic-best 53.79 meters (167 feet, 5 inches) in the discus.
"Bryan Clay is king now," said Roman Sebrle of the Czech Republic, the world-record holder and 2007 world champion who finished sixth, "and I was before. It was just about me giving him the crown for the next four years."
Clay led by a nearly insurmountable 479 points going into the final event. It was the 1500 metres, and Clay was so exhausted he could manage little more than a trot around the track in 5 minutes, 6.59 seconds.
When it was over, Clay sat on the track, then plopped on his back, chest heaving. Four years after settling for silver, Clay had wrested the decathlon title from Sebrle. He barely had the energy to celebrate.
Andrei Krauchanka of Belarus won the silver, Leonel Suarez of Cuba the bronze.
The 1.80-meter (5-foot-11), 84-kilogram (185-pound) Clay is the first American to win the decathlon since O'Brien at the 1996 Atlanta Olympics. He is small by decathlon standards, maybe the best athlete ever under 1.83 meters (6-feet).
"I'm OK with that," he said.
Clay was something of a troublemaker as a youngster.
"Graffiti and getting into fights," he said.
He went to school at Azusa Pacific, a small Christian college in suburban Los Angeles, where he still trains. Now 28, he still has the close support group he had then, led by coach Kevin Reid.
"I've seen him grow up," Reid said.
Grow up to become the greatest athlete in the world.
