Nigeria stunned the United States with a three-point win in Las Vegas in a Tokyo 2020 warm-up match ©Getty Images

Nigeria's basketball team stunned six-time defending Olympic champions the United States with a shock victory in a warm-up match for the delayed Tokyo 2020 Games.

Nigeria ran out 90-87 winners in Las Vegas to cause one of the biggest upsets in the history of the sport and condemn the US to their first defeat to an African nation.

The US, who have won every men's basketball gold medal but one at the Olympic Games since National Basketball Association (NBA) players were granted permission to compete before Barcelona 1992, had the chance to level late on but failed to execute their play at the Michelob Ultra Arena. 

The star-studded American team had beaten Nigeria 156-73 at the 2012 Olympics in London before recording a 110-66 win over the African side in an exhibition prior to Rio 2016.

Nigeria, led by NBA side Golden Warriors' coach Mike Brown, were in superb scoring form as they netted 20 three-pointers on their way to the upset victory.

The US had never been beaten by an African nation prior to the Tokyo 2020 warm-up against Nigeria ©Getty Images
The US had never been beaten by an African nation prior to the Tokyo 2020 warm-up against Nigeria ©Getty Images

US coach Gregg Popovich claimed the surprise loss could be a blessing in disguise for his team, which will seek a seventh gold medal in their last eight Olympic appearances at Tokyo 2020.

"In a way, I'm kind of glad it happened," Popovich said. 

"That means nothing if we don't learn from it. 

"It could be the most important thing in this tournament for us."

The US are in Group A for the men's basketball competition at Tokyo 2020, alongside Iran, France and the Czech Republic.

Nigeria are due to take on Australia, Germany and Italy in Group B.

Matches in the men's tournament at Tokyo 2020 are set to be held at the Saitama Super Arena from July 24 to August 7.