On a team of mostly first-time young Olympians, it was the USA veterans Carmelo Anthony and Kevin Durant who stole the Rio show as the USA won its third straight gold medal.

Anthony on Sunday became the first man to collect three basketball golds, a week after he became the USA's all-time Olympics scorer, surpassing NBA superstar LeBron James.

But Kevin Durant, the only other player besides Anthony to return from the 2012 London Games, provided a big assist by unleashing his potent offensive punch to clinch the title.

The newly assembled team they led was occasionally challenged in Rio, raising some doubts about the outcome.

But not in the minds of the USA players, said Durant.

"We got together on July 17 and we set our minds on winning these gold medals. That was our main focus, Carmelo being the leader and me kind of following up," he said.

Anthony, 32, brought the experience, and Durant, 27, the scoring as the USA capped their 2016 Olympic run by mauling Serbia 96-66.

Anthony was on the 2004 team that settled for bronze, a hard-to-swallow result that sparked a re-organisation of the USA programme.

"It's really hard to understand it and have a feeling about it when you're going through it," he said of his four Olympic appearances for the USA, also a men's record.

"Not until you have some time to yourself, you get a chance to reflect back on this journey starting back in 2004 up until now.... I don't think I can explain how I feel right at this moment."

Too unselfish

Still a top NBA scoring threat with the Knicks, he finished as the USA's second-highest scorer at the Rio Games with 12.1 points per game, after Durant's 19.4.

His offense was critical in a group-stage contest against Australia -- which had four NBA champion players on its roster and was the first team in Rio to threaten an upset.

But Anthony stepped up with a game-high 30 points against the Aussies, including 14 in the fourth quarter to help lock the game down.

He won't go for a fourth gold, however.

"As much as I'm going to miss it, it's time to pass it on to some of the guys who were here and some of the younger guys that are coming along," he said.

Durant, who is headed to the Golden State Warriors, scored 30 points on a series of highlight-reel plays Sunday to ignite the Serbia rout.

He admitted that was trying to be too unselfish in earlier games.

"Coach (Mike Krzyzewski) sat me down and showed me some film of 2010 and he said, 'I want to see that guy again,'" Durant said.

"I was trying too hard to sacrifice and make that extra pass, and I was taken away from my game. But coach just told me to be me and I went out there and I did that."

It was Krzyzewski's last game leading the USA. The Duke University coach, a five-time NCAA title winner, will hand over to San Antonio Spurs coach Gregg Popovich.

He praised Anthony and Durant for their long-term commitment to the USA team.

"It sets the example for a younger generation in the United States to where now everybody is proud of USA basketball. It's not just how they play, but how they acted and how unselfish they were," he said.