Caster Semenya dismantled the field in clinical fashion, fulfilling her role as prohibitive pre-race favourite, to clinch a history-making first women’s Olympic track gold for South Africa.
The powerful Semenya, who won silver at the London 2012 Olympic Games and is unbeaten this season, kicked hard off the final bend and flew down the final 100 metres for a comprehensive victory by chipping 0.05 from her national record in 1:55.28.
"I dedicate this to my team," said a stunned Semeya, still comprehending her feat despite being the overwhelming favourite. "They've done a fantastic job. It's a great feeling. Just fantastic. I couldn't believe it. Just fantastic."
Behind her, world indoor champion Francine Niyonsaba grabbed silver in 1:56.49 to become Burundi’s first ever female Olympic medallist. It is also just the second ever Olympic medal for her country, 20 years after Venuste Niyongabo won the men’s 5000m gold in 1996.
Bronze went to the 20-year-old emerging Kenyan talent Margaret Wambui, who out-fought Melissa Bishop of Canada in a tight tussle down the home stretch to stop the clock in a PB of 1:56.89.
On a still and clammy night inside the Olympic Stadium, it was Semenya who grabbed control of the race from the gun, leading the field through 200m followed closely by Niyonsaba with world champion Marina Arzamasova of Belarus tucked in close behind.
Maintaining a healthy pace, the South African hit 400m in 57.59 running virtually shoulder-to-shoulder with the much more diminutive Niyonsaba, followed closely by Arzamasova and Canada’s world silver medallist Bishop.
The bell was the calling card for Niyonsaba to make her gold medal bid as she accelerated to the front pursued by a composed-looking Semenya, with Wambui also keeping close to the front.
Around the final bend, the 25-year-old Semenya stepped on the gas with devastating effect and within what appeared a handful of strides she streaked past Niyonsaba, who appeared almost static by comparison.
Once in front, Semenya was not going to surrender her lead and she devoured the remaining distance to create a piece of history and get her first global title since winning the 2009 world title.
Behind, Niyonsaba held on comfortably to the silver medal position, but the closest battle was the fight for bronze. Halfway down the home straight, Bishop held a slight lead from Wambui but the Kenyan gradually forced her way past the Canadian to grab the final spot on the podium and ensure an African 1-2-3.
Bishop, although without a medal, had the consolation of trimming 0.41 from her national record to post 1:57.02.
Finishing with an eye-catching late burst like in her semi-final, Joanna Jozwik of Poland grabbed fifth place in a lifetime best of 1:57.37 and in a high-class race Lynsey Sharp of Great Britain also set a PB for sixth in 1:57.69.
Steve Landells for the IAAF