Russia's Tatyana Lysenko clinched gold in the women's hammer final
with an Olympic record throw of 78.18m
, but there was disappointment for Britain's Sophie Hitchon.
Lysenko demolished the field with her fifth attempt in the Olympic Stadium.
Poland's Anita Wlodarczyk secured silver with a 77.60m throw while Germany's Betty Heidler clinched a controversial bronze.
British record holder Hitchon, 21, finished 12th with a 69.33m effort.
The Burnley-born former ballet dancer had qualified for the final with an
impressive throw of 71.98m
to improve her British record by 37cm.
But Hitchon was unable to repeat her efforts in qualifying and bowed out of the final early.
Lysenko, 28, led all the way through the competition, having thrown 77.56m with her first attempt, before going even further with her penultimate effort.
Heidler denied China's Zhang Wenxiu a bronze with a throw of 77.13m.
The bronze initially went to China before it was discovered the German's best throw had been measured incorrectly by officials. An appeal by China was rejected.