USA Basketball’s latest attempt to field a Dream Team got off to a nightmarish start.

Taking their first step toward the Tokyo Olympics, Kevin Durant, Damian Lillard and Co. fell to Nigeria, ­90-87, in their exhibition opener Saturday night in Las Vegas. The Nigerians, who are coached by Golden State Warriors assistant Mike Brown, hit 20 three-pointers to pull off an enormous upset against the world’s leading basketball superpower. It was the Americans’ first loss to a team from Africa.

In a previous meeting between the countries, during the 2012 London Olympics, the Americans won in a 156-73 blowout. Saturday’s stunning loss came after one oddsmaker favored the top-ranked Americans by 29½ points to beat the 22nd-ranked Nigerians, who were led by several players with NBA experience, including Gabe Vincent and Josh Okogie.

“In a way, I’m kind of glad it happened,” Team USA Coach Gregg Popovich said. “That means nothing if we don’t learn from it. It could be the most important thing in this tournament for us. ... Everybody expects us to win every game. That puts some pressure on you. For a new group, in tough circumstances, I thought they did a good job of not getting down, not blaming anybody and just playing. That will go a long way.”

Team USA, which had been 54-2 in exhibition games since 1992, assembled a loaded roster for a minicamp in Las Vegas. Seeking redemption for an embarrassing seventh-place finish at the 2019 FIBA World Cup, Team USA brought together Durant, Lillard, Jayson Tatum and Draymond Green, among other all-stars, in search of its fourth consecutive Olympic gold medal.

However, the U.S. squad was at a disadvantage from a preparation standpoint. While the Americans had four days of camp, the Nigerians had trained together for weeks in the Bay Area. Team USA also was missing three players — Devin Booker, Jrue Holiday and Khris Middleton — who are in the NBA Finals matching the Phoenix Suns and Milwaukee Bucks.

“I thought that the Nigerian team played very physically,” Popovich said. “They did a great job in that regard, and they knocked down a lot of threes. Give them credit. ... We have to find out why they got so many threes and what we need to do defensively to shore that up. That was the difference in the game.”

Down the stretch, the Americans looked like a group that had only recently assembled. Needing stops, they repeatedly got lost in defensive rotations and conceded open three-pointers.

Despite its high talent level, the Team USA roster is light on pass-first distributors, a deficiency that proved problematic in the fourth quarter. On a key late possession while facing a three-point deficit, the Americans burned nearly 10 seconds of clock trying to set up a game-tying shot, only for Zach LaVine to be fouled and sent to the line for two free throws.

Durant, who never touched the ball on the crucial possession because he couldn’t shake free from his defender, led his team with 17 points. Tatum, who added 15, said the Americans were “still getting to know each other” after the abbreviated training schedule and added that a lack of ball movement contributed to their offensive shortcomings.

“It’s only been four days. We’re making strides. None of us had ever played with each other,” the Boston Celtics forward said. “[At times], we reverted to NBA [isolation], one-on-one [basketball], and that’s not going to get it done.”

The 25-year-old Vincent, who appeared in 50 games for the Miami Heat this season, scored a game-high 21 points and hit six three-pointers to lead Nigeria.

“We knew we could play well against a great team,” said Vincent, a 6-foot-3 guard who went undrafted out of UC Santa Barbara in 2018. “There was a lot of doubt put on us, for us to get blown out or the game to get out of hand early. If anything, that put a chip on our shoulder.”

Brown understatedly called the upset a “good win” for Nigeria.

“I’m happy for our guys. They’ve worked hard,” Brown said. “The phone is blowing up. Hopefully people will join the bandwagon. We need a lot of love.”

The U.S. team continues its exhibition schedule with four more games in Las Vegas, starting with a contest Monday against Australia.