Sanya Richards shook off years of disappointment Tuesday with her first major title in the 400 meters, pumping her fist after crossing the line at the world championships.

Her main rival, Olympic champion Christine Ohuruogu of Britain, was back in fifth. And for Shericka Williams of Jamaica, it was silver again.

"I finally got it right," Richards said. "It means the world to me."

With a time of 49.00 seconds, Richards set the fastest mark of the year. It was good news for the struggling U.S. team, which had been unable to keep Jamaica from celebrating in the sprint events.

At the Beijing Olympics last year, Richards faltered over the last 50 meters and Ohuruogu won. Not so this year. In the shadows of the Usain Bolt vs. Tyson Gay showdown, this duel was nearly as good.

Richards, in Lane 3, had a clear look at defending champion Ohuruogu in Lane 7 and she caught up with her over the first 300 meters. Then she only had to focus on the finishing line.

"She wanted it a little bit more than the rest of us," Ohuruogu said.

Richards was 0.32 seconds faster than Williams. Antonina Krivoshapka of Russia took bronze.

The American crossed the line with her arms raised in celebration, showing utter disbelief that so many failures finally ended in victory. With a grin on her face, she danced a little number for screaming fans.

Not only did she keep all competition at bay, she also shook off another flare-up from Behcet's syndrome, a rare disorder that causes chronic inflammation of blood vessels throughout the body.

Two years ago, she struggled with the disease when she failed to qualify for the worlds in Osaka, Japan. This time, the lesions on her legs, her stomach and inside her mouth were not going to conquer her.

Her legs cramped up with gold in sight at the Beijing Games. That made it all the sweeter at worlds.

"Finally, I own a major title," she said with gold around her neck on the podium. "Before, I had difficulties standing the pressure. But now I am a better athlete."

She looked beyond the imposing grey stone of the Olympic Stadium and up at an evening sky filled with wispy pink clouds.

Completing a good day for the U.S. team, Kerron Clement successfully defended his 400-meter hurdles, holding off a late challenge from Javier Culson of Puerto Rico.

It left the United States on top of the medals table with three gold and seven overall, ahead of Russia with two titles and seven medals overall. Jamaica has two gold and five overall.

Bolt, meanwhile, was looking to impose his dominance in the 200.

Going for his second gold medal of the worlds, Bolt jogged across the line to advance to the semifinals of the 200.

Two days after setting a world record of 9.58 seconds to win the 100, the Olympic 200 champion ran a good curve and coasted through the final straight to finish in 20.41 seconds, a full 1.11 seconds behind his world record.

In the absence of injured defending champion Gay, Bolt is the overwhelming favorite for gold, and he said he would try to get a second world record at the championships, too.

"I'll be running hard," Bolt said.

The Jamaican set a record of 19.30 seconds at the Beijing Olympics, widely considered one of the toughest to beat in the sport.

"I'm just trying to get through the rounds. That's my aim," Bolt said. "I'm trying to do it round by round like last year. Then I'll go to the finals and just execute."

After his wild celebrations and showboating after winning the 100 on Sunday, he was short on antics this time. Blame it on fatigue since he had to be in the stadium early Tuesday morning for the first heat.

"I'm feeling a little tired, but nothing a good night's rest won't cure," Bolt said after his sixth race in four days.

Jamaican teammate Steve Mullings had the best qualifying time, winning his heat in 20.23. Shawn Crawford was third in 20.37, with American teammate Wallace Spearmon also easily advancing.

The final for the 200 is set for Thursday. Bolt is also favored to lead Jamaica to a sprint relay gold on Saturday to equal his feat of three golds at the Olympics.

If the loss of Ohuruogu was a setback for Britain, Phillips Idowu made up for it, winning the triple jump ahead of Olympic champion Nelson Evora of Portugal.

Kenya continued its supremacy in the steeplechase. Ezekiel Kemboi, the 2004 Olympic champion, won gold ahead of Richard Mateelong and set a championship record of 8:00.43. Bouabdellah Tahri of France settled for the bronze but set a European record.

In the 100 hurdles, two-time defending champion Michelle Perry was eliminated in the heat, finishing seventh. Perry injured her right knee in Monaco and had to fight to make the started block.

"It was a victory in itself," Perry said.

She is set to have surgery at home next week.

The United States still looked strong, with Olympic champion Dawn Harper and Damu Cherry both qualifying from their heats.

Priscilla Lopes-Schliep of Canada had the top time of 12.56, ahead of Jamaican veteran Brigitte Foster-Hylton, who finished in 12.67.

Olympic champion LaShawn Merritt and defending champion Jeremy Wariner easily qualified for Wednesday's semifinals of the 400.

In the discus, overpowering Olympic and defending world champion Gerd Kanter qualified on his first throw.

The host nation won its first gold when Steffi Nerius won the javelin ahead of favorite Barbora Spotakova of the Czech Republic.