Belarus shot putter Nadezhda Ostapchuk has been stripped of the women's Olympic title after failing a drugs test, elevating New Zealander Valerie Adams to champion.
Ostapchuk, the 2005 world champion, had a winning throw of 21.36m a week ago in London as Adams, the defending Olympic and three-time world champion, threw 20.70m.
"It is taking me some time to take this in," Adams said from her base in Switzerland.
"It is huge and I am absolutely thrilled of course. It makes me extraordinarily proud as a New Zealander.
"It is also encouraging for those athletes, like myself who are proud to compete cleanly, that the system works and doping cheats are caught."
Ostapchuk was the 12th athlete at the Olympics to be excluded following doping tests, but the first to lose a medal.
The decision means New Zealand moves up one place to 15th on the Olympic medal table with a total of six golds, two silvers and five bronzes.
Russia's Yevgeniya Kolodko now gets the silver medal and Lijiao Gong of China the bronze.
Ostapchuk finished fourth at the Athens Olympics in 2004 and took bronze in Beijing four years ago.
The International Olympic Committee (IOC) said the 31-year-old Belarussian provided two urine samples which contained the banned anabolic agent metenolone.
"The athlete was first requested to provide a urine sample for a doping control on 5 August," the IOC said.
"She competed the next day in the women's shot put event, where she placed first, and was asked to provide a sample straight after her competition.
"Both samples indicated the presence of metenolone, which is classified as anabolic agent under the 2012 Prohibited List."