American Michael Norman made up for a disappointing fifth-placed finish at the Tokyo Olympics by winning the world 400m gold in Eugene on Friday.
Norman, who failed to advance from the semi-finals in the Doha worlds in 2019 with a thigh injury, clocked a winning time of 44.29 seconds, AFP said.
Three-time Olympic medalist and 2011 world champion Kirani James of Grenada claimed silver with 44.68sec, while Briton Matthew Hudson-Smith took bronze (44.66).
"It is an amazing feeling for sure. Just to come out here on a home track and pull out with a gold individual medal," said Norman.
"It is going to be a memorable one. I want to remember what took me here and I am just thankful to everybody who supported me throughout my whole career.
"Without those people, I would not be where I am right now. So I really appreciate all those people. It took a lot of work to get where I was - obviously last year was not a good year for myself so I had to do a lot of hard work just to kind of get back to where I was.
"I just wanted to make sure that I did everything that I could have possibly done to become the new world champion."
James said he knew it "was always going to be a battle" with Norman.
"I thought I had a good advantage to beat him to see him in front of me. But catching him, it is never going to be easy.
"For me, I am just grateful to compete against these guys at this competitions, putting on a show for the fans, that is what the track and field is all about."
James added: "If the fans enjoy it, they get excited, the sport grows and I am happy. This medal is special because after every Olympics, you always want to come back and show that you are consistent."
World record holder Wayde van Niekerk of South Africa, who set the record of 43.04sec when winning gold at the Rio Olympics in 2016, finished fifth in 44.97sec.
A serious knee injury saw Van Niekerk take a three-year hiatus from the sport in the wake of Rio, his comeback itself tough due to the Covid-19 pandemic and paucity of meets he attended.
"As the world record holder, this is where I belong," the South African said.
"This is what I need to fight for. I need to make sure that I do whatever it takes to patiently get myself back to the place where I belong and that is on the podium.
"Fifth this time around, so I am working definitely towards the goal. Hopefully next time, I am on the podium."
Bahamian star Steven Gardiner, the reigning world and Olympic 400m champion, was a notable absentee from Eugene, missing the worlds because of an inflamed tendon.