U.S. women win the first Olympic gold in three-on-three basketball.

TOKYO — Every game of three-on-three basketball, which made its debut this summer as an Olympic sport, began the same way: a countdown from 10 over the arena speakers that finished “five … four … three … X … THREE!”

Kelsey Plum, a member of the American women’s team, described the scene as “pandemonium, like you’re shot out of a cannon.”

Time will tell whether three-on-three — or 3×3, as it is officially known here — catches fire as an Olympic sport, but the five-day run of games at the Aomi sports complex in Tokyo provided precisely the type of spectacle that its organizers had hoped for: a high intensity, visually dynamic, low-bar-of-entry diversion from the more structured feel of five-on-five basketball.

With a higher standard for fouls, players grappled like wrestlers. With few breaks in play, they huffed for air like sprinters.

The United States women ended their Olympic experience with a bang, cruising to a 18-15 win over the Russian team in the gold medal game. Stefanie Dolson led the team in scoring with 7 points.

The Americans were one of the favorites in the tournament, a group of W.N.B.A. players tossed together only recently but expected to succeed on the basis of their superior skill. (Jackie Young joined the squad on July 19 after Katie Lou Samuelson tested positive for the coronavirus.)

And they delivered, going 6-1 in the pool stage, dropping their only game to Japan, the host nation.

Their final day of competition began with a tough semifinal matchup against France, an athletic squad that ran a smooth offense. Sunlight and shadows streaked across the court for the early evening game, and the day’s stifling heat left players on both teams gasping for air and holding ice packs on their bodies. The United States won, 18-16, after holding off a late French surge.

The gold medal game, in comparison, was a far less stressful affair. With Thomas Bach, the president of the International Olympic Committee, occupying a first row seat, the Americans mostly had their way with the Russians, getting to the basket with relative ease.

Plum had 5 points and Allisha Gray added 4.

When the buzzer sounded, the four players embraced in the middle of the court, the first ever winners of an Olympic gold medal in a fledgling, raucous sport.