The United States outclassed defending Olympic champions China to set the pace in the women's gymnastics qualifying round on Sunday but suffered a shock as their top name, world all-round gold medalist Jordyn Wieber, failed to make the individual final.
Wieber, one of the biggest medal favorites coming into the Games, finished behind team mates Aly Raisman and Gabby Douglas in the all-round standings, meaning she has no hope of getting one of the two U.S. places in Thursday's fight for the individual title.
The U.S. team held on to their qualifying lead when China, featuring He Kexin and Deng Linlin, two of the team gold medalists from the Beijing Games, put in less-than-stellar performances.
He finished behind Briton Beth Tweddle on the asymmetric bars, for which she won gold in Beijing, and the team failed to get a gymnast into the top eight of the vault and floor, shutting them out of the individual finals in both disciplines.
Yao Jinnan, the world all-round bronze medalist, banged her head and leg in a bad landing from the vault and was bandaged up by her coach.
With former Olympic champions Romania and Japan still to compete at the North Greenwich Arena, the U.S. led Russia by 181.863 points to 180.429. China were third, nearly four points behind.
Home team Britain, cheered on by rows of uniformed soldiers filling previously empty prime seats, lay fourth.
Wieber, 17, paid the price for a series of wobbles on the bar and a slight overstep on the floor as Raisman and Douglas, with whom she won the world team title last year, nailed slicker routines.
The 16-year-old Douglas, who beat Wieber in the U.S. trials, had a big overstep on the floor herself, incurring a 0.3-point penalty, but did well enough on the other apparatus for the mistake not to matter.
"Today (Jordyn) wasn't quite as sharp," U.S. team coordinator Marta Karolyi told reporters. "Aly's success today just proves that hard work pays off."
"It was always going to be close between the three of us doing all-round and in the end it is what it is," Wieber told the Olympic news service after avoiding the world's media.
"It was hard because of course I wanted that spot but I also wanted Aly to do her best for the team."
Thanks to China's poor showing, Wieber maintains a slim hope of reaching the individual floor final, depending on results in the day's last qualifying session, but it would be her only compensation.
The top eight teams, the best eight on each apparatus and the leading 24 individuals in the standings at the end of the qualifying competition on Sunday get to compete for medals.
Russian Victoria Komova, who lost out to Wieber for the world all-round title by 0.033 points last October, led the individual standings after high scores on the beam and asymmetric bars, just ahead of Raisman with Douglas third.
Britain's Tweddle ensured she would have a chance to add an Olympic gold to her two world titles on the asymmetric bars with a stunning routine, and the day's highest mark of 16.333, on the apparatus.
Tweddle, 27, had been unhappy with her floor mark of 14.433, but was all smiles after the bars, her final event.
"I am really pleased with the routine, I couldn't have asked for any more than that," she told reporters.
Tweddle, who has come back from knee surgery three months ago and sleeps with a hi-tech ice machine strapped to her leg, was delighted with the support from the soldiers.
"We got a standing ovation as we walked back along. It was amazing," said Tweddle. "It was so bizarre to suddenly see half a crowd of soldiers but it was really nice for them."
Uzbekistan's only representative in the gymnastics, Luiza Galiulina, who had been due to compete on Sunday, was provisionally banned from the Games after testing positive for a diuretic.
Her coach, Uzbek-born Oksana Chusovitina, who now competes for Germany, made a record sixth appearance in the Olympics at the age of 37, in Sunday's qualifiers.
Chusovitina declined to talk about Galiulina but was happy to discuss her qualification for the final of the vault, on which she won a silver medal in Beijing.
Asked how she felt, she told reporters: "Very good, as if I was 18 again. I have got in the final and I'm happy. My age doesn't matter because when you are in the arena everybody's judged the same.
"Every time I'm proving something to myself. I could do something else but while I can do this, why not?"
(Additional reporting by Mark Trevelyan; Editing by Kevin Liffey)