Kenyan Eunice Sum spoilt the Russian party on the final day of the world championship with a late burst through the middle to deny home favourite Mariya Savinova back-to-back 800 metres titles on Sunday.
Unheralded Sum, the Kenyan trials winner, powered past the Russian Olympic champion on the home straight and threw her arms into the air as she crossed the line in a personal best time of one minute 57.38 seconds.
Savinova was second in 1:57.80 and American Brenda Martinez snatched third (1:57.91) from her compatriot and long-time race leader Alysia Johnson Montano who threw herself over the line before dissolving into tears.
Montano, fastest in the semi-finals, pulled away from the start and led by 10 metres at the bell but was clearly tying up as the athletes rounded the home bend and had nothing left to give in the dash for the line.
Meanwhile, Kenyan Asbel Kiprop put last year's Olympic disappointment firmly behind him with an emphatic 1,500 metres world title defence.
The long-striding Kiprop's devastating finishing kick quickly took him clear when he loomed up on team mate Nixon Kiplomo Chepseba's shoulder around 80 metres from home and he coasted over the line in 3:36.28.
Kiprop, Olympic champion in 2008, finished last in London when he was nursing a hamstring injury but has been in hot form this season, including a scintillating run in Monaco last month when he became the fourth fastest of all-time at the distance.
In the battle for minor medals, American Matthew Centrowitz (3:36.78) took silver and South African Johan Cronje (3.36:83) bronze.
Algeria's Olympic champion Taoufik Makhloufi missed the championships through illness.