(From L) USA's Natasha Hastings, Phyllis Francis, Allyson Felix and Courtney Okolo celebrate after they won the Women's 4x400m Relay Final(From L) USA's Natasha Hastings, Phyllis Francis, Allyson Felix and Courtney Okolo celebrate after they won the Women's 4x400m Relay Final (AFP Photo/Pedro Ugarte)
Rio de Janeiro (AFP) - Allyson Felix is targeting next year's World Championships after bagging a record sixth Olympic gold as the United States defended their 4x400m crown.
Felix, the reigning 400m world champion, crossed in 3min 19.06sec, with Jamaica winning silver in 3:20.34 and Britain claiming bronze in 3:25.88.
The win came only 24 hours after Felix had picked up a fifth gold medal in the 4x100m relay.
She now has more Olympic golds than any other woman track and field athlete in history.
"It's amazing to come together with these women tonight and to be able to finish it off. It was a good night," Felix said.
The relay golds offset the disappointment of an individual season disrupted by a freak ankle injury after a gym accident.
That setback left her scrambling to regain full fitness, ending her hopes of a 200m-400m double in Rio.
She suffered an agonizing defeat in the final of the 400m and failed to qualify for the 200m after missing out at the US trials.
Asked to assess her season, she replied: "The toughest without a doubt. You make plans and you want things to go to a certain schedule -- and nothing went according to the schedule.
"But that's okay, it's about growth and character and I think I learned a lot of lessons throughout this Olympic Games."
The conclusion of her fourth Olympics -- she made her debut at the Athens 2004 Games -- left Felix reflecting on her career with satisfaction.
"I can look back at the things I've accomplished and be really proud," she said.
"And really be grateful for what track and field has brought to my life. I'm really passionate about it and it's brought me a lot of joy."
Her medal collection will remain with her parents though.
"They like to show them off. I let them do that," she said.
Felix expects to race once more in Europe this year before turning her attention to the World Championships in London next August when she will be 31.
She would not be drawn on the possibility of returning for a fifth Olympics in 2020.
"London is next on the agenda," she said. "As far as the next four years -- I'm just taking it year by year. I think that I probably have one more race this season, maybe in Zurich."
The relay win was the latest in a a 20-year unbeaten reign in the event for the United States.
They have not lost a 4x400m relay since finishing in silver behind the unified team of former Soviet Union states at the 1992 Barcelona Games.