Rio de Janeiro: Kenya’s Faith Kipyegon produced a startling last-lap sprint to outpace overwhelming favourite Genzebe Dibaba of Ethiopia to win Olympic 1500m gold on Tuesday.

Kipyegon clocked 4min 08.92sec after her burst over the last 250 metres, world record holder Dibaba taking silver in 4:10.27.

American Jennifer Simpson claimed bronze in 4:10.53.

American Shannon Rowbury and Britain’s Laura Weightman, who also competed in the 1500m at the 2012 London Games from which six of the top nine finishers have since been disqualified for doping, took up the early pace and it was slow.

With two laps to go at the Olympic Stadium, world champion Dibaba surged to the front, the field immediately strung out with the added pace.

Dibaba held her lead through the bell for the final lap, but was expertly reeled in with under 250 metres to go by Kipyegon.

The 22-year-old Kenyan, who won silver behind Dibaba at last year’s world championships in Beijing, pulled level with and then away from the Ethiopian in an incredible display of finishing.

Dibaba, who after breaking the world indoor mile record and winning the world indoor 3000m title at the start of the year was forced to delay the start to her outdoor campaign due to a troublesome toe injury, began to tie up as the line approached.

But the 25-year-old just managed to hold on for silver from 2011 world champion Simpson, whose bronze was the United States’ first ever Olympic medal in this event.

The race four years ago at the London Games gained notoriety for all the wrong reasons.

A staggering six of the top nine athletes competing four years ago were disqualified for doping violations, the race going down as being the one of the most tainted in Olympic history.