Aliya Mustafina upset the favourites by taking the gold medal on the asymmetric bars in the gymnastics apparatus finals at the London Olympics after all-around champion Gabby Douglas fluffed her routine.
Mustafina collected Russia's first gymnastics gold on these games, finishing with 16.133, 0.2 points ahead of defending champion He Kexin of China.
Home favourite Beth Tweddle bade farewell to the Olympics at the age of 27 with a bronze medal to add her contribution to the British team's best tally in the sport.
American teenager Douglas, competing last, took a free swing after hesitating on the higher bar and suffered with a score of 14.900 and last place.
The gold medal completed a set for the 17-year-old Mustafina, after she won team silver and all-around bronze last week.
Her team mate, the world and European bars champion Victoria Komova, who spent much of the first week in tears after missing out on all-around and team gold, had been expected to be Russia's biggest medal hope on the apparatus.
Judging by Komova's miserable expression as she stepped down after finishing her routine, however, the teenager already knew she had missed out again and she ended up fifth with 15.666.
Mustafina, by contrast, was a picture of smiling delight as she finished her routine and high-fived her coach. She has now outdone her father, Greco-Roman wrestler Farhat Mustafin, who won a bronze at the 1976 Montreal Games.
China's He, who was at the centre of allegations in Beijing that the home team were fielding under-age gymnasts - charges they denied, set the standard when she opened the final with a dazzling routine and a mark of 15.933.
Mustafina was sixth up and then waited to see if Douglas, starting last, could follow up on her all-around and team golds.
Douglas, 16, is known as the "Flying Squirrel" for the shape she makes on her favourite apparatus but could not reproduce her form of last week.
American fans at the North Greenwich Arena suffered with her as she averted her gaze from the scoreboard while waiting for her mark to flash up.