Cameroon's Francoise Mbango Etone broke Greek hearts on Monday night by pipping home favourite Hrysopiyi Devetzi to triple jump gold.
Mbango Etone leapt 15.30 metres in the second round to see off the challenge of Devetzi by just five centimetres.
Russia's world champion Tatyana Lebedeva could only take bronze after jumping 15.14m with her final effort.
Yamile Aldama, the Cuban-born athlete who wanted to compete for Britain but was denied a passport, finished fifth.
Mbango Etone, who jumped the exact winning distance again with the last of her six jumps, became the first Cameroon woman to win Olympic gold.
"I am very proud to get the medal and the African record," said the 28-year-old.
"I knew I had a chance because I felt strong all year.
"I tried to stay below the radar so I could surprise the competition and I'm pleased the strategy paid off."
Despite settling for silver, Devetzi produced the longest jump in Athens in the qualifying competition.
Her leap of 15.32m was a Greek national record and was the third best leap of all time by a woman.
Bronze medallist Lebedeva will now turn her attention to the long jump, where she also has medal hopes.