LONDON — Members of the United States women’s gymnastics team, clad in shiny, sparkly red uniforms, stood together and stared at the scoreboard at the end of the team competition, looking frozen as they waited for the news they knew would come.


They had just knocked out a series of such solid performances that they led the competition from start to end, widening the gap on their competition with each event. But they saved their celebration for the moment it was official.


When the United States popped up at the top of the leader board, they smothered one another in hugs as chants of U-S-A roared throughout the arena.


The team, which is the reigning world champion, won the first Olympic team gold medal for the United States women since the Magnificent Seven won it in 1996. And it did it in dominating fashion.


The United States beat Russia by the wide margin of 5.066 points, giving the Russians the silver medal. Romania won the bronze, with 7.182 points — which is a galaxy away from the Americans.


China finished fourth, failing to defend the Olympic gold medal it won at the 2008 Beijing Games.


The Russians and the Chinese, who at some point in the night were within striking distance of the gold medal, were heartbroken. They sobbed as the Americans celebrated.


For Jordyn Wieber, the reigning world champion in the all-around, the victory was sweet redemption after she failed to qualify for the all-around final. She was third among the Americans in all-around qualifying, and every team can send only its top two gymnasts.


But she did not let that disappointment break her, performing solidly as the United States took the lead after the first of four events, then kept it.


It started off strong on the vault.


The Americans landed three strong vaults, each the very difficult Amanar vault, which is one flip with two and a half twists. For some countries, it is an impossibility that even one gymnast can land it. The entire United States team in finals, though, landed it with ease.


Wieber started off the Americans’ effort with a vault that received a score of 15.933. Gabby Douglas was next, with 15.966 points.


Then came the exclamation point: McKayla Maroney, the world champion on vault, scored 16.233 points after getting so much air that she nearly hit the rafters. Afterward, she flashed a huge smile and danced off the floor.


The United States led the competition, with China in second and Russia in third. But the Chinese started to crumble with a string of errors on the balance beam and the floor exercise.


The Russians, however, held it together until their final event — the floor exercise. Anastasia Grishina totally balked on one of her tumbling passes, leaving it out then leaving the floor fighting back tears. Next, Kseniia Afanaseva, the reigning world champion on floor, landed her final tumbling pass on her knees and nearly her head.


Minutes later, nearly the entire Russian team was in tears as they sat against the arena wall and watched the Americans tumble.


Douglas went first for the United States, gracefully tumbling and dancing like a long, lean prima ballerina. Wieber went next, knocking out a powerful routine anchored by her draw-dropping tumbling.


When the team captain Aly Raisman walked onto the floor to perform last, the medal was all but in their hands. Raisman, who won the bronze medal in the event last year, is usually stone-faced when she competes. But on this night, she appeared to be fighting off a grin.


As her teammates cheered her on and “Hava Nagila” blasted through the arena’s speakers, Raisman landed pass after pass as the arena grew louder. When she was done, she walked off the floor toward her teammates, who were exchanging bearhugs with their coaches, and with one another.