Ukrainian fencer Yama Shemayakina won epee gold but the headlines were grabbed by Shin A Lam on a day of controversy at the ExCel Arena.
The South Korean forced a lengthy delay to competition after breaking down in tears following her semi-final loss to German Britta Heidemann.
Shin looked to have beaten Heidemann only for the clock to be reset with one second remaining of sudden death.
Heidemann then managed to score a decisive hit for a 6-5 win.
"Ukraine have got a gold medal from nowhere there. We have seen some excellent fencing today. It has been a very, very entertaining women's epee contest."
The result angered the South Korean camp, who appealed. But their protests were ignored and Shin's coach was eventually escorted from the arena.
"I don't really know how to express the way I feel right now," said Shin. "I've been trying and working to get an Olympic medal for four years. Now I lost it in just one second. It's just impossible to accept."
Level with 2008 gold medallist Heidemann at 5-5 following nine minutes of action, Shin had priority, meaning she would have made the final if she had made it through the sudden-death minute without conceding a point.
But referee Barbara Csar reset the time with one second left after Shin was guilty of an infringement and Heidemann scored the crucial point.
Shin broke down in tears and her coach made his objections clear, but, after lengthy deliberation between technical directors and then officials from the International Fencing Federation, Heidemann's win stood.
After the 70-minute delay, Shin reappeared for her bronze-medal match but was beaten 15-11 by China's Yujie Sun. Shemyakina overcame Heidemann 9-8 in extra-time to win the gold.
Great Britain's Corinna Lawrence
failed to make the last 16.