Richards-Ross of U.S. wins women's 400m gold

Last Updated 5:44 p.m. ET

(CBS/AP) LONDON -

This time, Sanya Richards-Ross closed the deal.

Four years after a late fade left her crying and wearing bronze at the Olympics, Richards-Ross won the 400-meter gold she always thought she should win.

Nearly banging elbows with runners on both sides of her - and with the defending champion making up ground on the outside - Richards-Ross got stronger, not weaker, this time over the last 100 meters.

She surged to the finish, won by about a body's length and punched her fist when she crossed the line in 49.55 seconds Sunday night to give the U.S. its first track and field gold medal of the London Olympics.

Defending champion Christine Ohuruogu of Britain finished second in 49.70 and American DeeDee Trotter, decked out in red, white and blue glitter on her face, won the bronze in 49.72.

This moment, though, belonged to Richards-Ross. At the end, she wrapped herself in the American flag and went to the stands to embrace her husband, Jacksonville Jaguars defensive back Aaron Ross, who took time off from NFL training camp to travel to London.

"You finally did it, you finally did it, babe," he told his wife. "Enjoy the moment."

Ethiopia's Gelana wins women's Olympic marathon
Venus and Serena Williams win Olympic gold
Farah wins 10,000 m. on golden night for Britain
Jessica Ennis wins heptathlon, Britain's first track gold

Imagine what the trophy case at their house must look like. Ross has two Super Bowl rings. His wife now has an individual gold to go with two others she won in previous Olympic relays, with one more possible next week in another relay.

The world's top runner at this distance for much of the last four years, Richards-Ross has nonetheless been waiting impatiently for another shot at the individual gold she thought she'd grab in 2008.

That time, the final 100 meters of her race was a disaster. Leading coming into the stretch, she fell back dramatically, and a few minutes later, she was crying in the lower level of the Bird's Nest.

Quite a different result this time and quite a different scene at the finish.

"She worked so hard," Aaron Ross said. "All the emotions going through her mind, my mind, her family's mind, everybody that's seen the struggles. It just a great moment right now."

Health issues almost certainly contributed to the bronze medal in Beijing. Richards-Ross spent five years fighting an autoimmune disease called Behcet's syndrome, but after a visit to a different doctor, she thinks she's been misdiagnosed.

Fighting her illness - which causes fatigue, sores around her mouth and splochy skin - with a new treatment, the five-time U.S. champion arrived in London feeling as good as she has in years.

It showed in this race - the warm-up act for the men's 100-meter final won by Usain Bolt.