Laura Trott landed gold in the women's omnium after she obliterated her closest rival, American Sarah Hammer, in the 500m time trial at the London 2012 Olympics.
It is Trott's second gold medal in under a week and Great Britain's 21st gold of these London Games.
Fifth coming into the final bend of the scratch race phase, the world and European champion sprinted hard on the final lap but was unable to overtake Australia's Annette Edmondson, and American Sarah Hammer.
Placed in the silver medal position, Trott had to clock in the fastest in the 500m time trial to take gold with Hammer leading.
Trott needed to finish three places ahead of the Californian to take her second gold of the Games, after her team pursuit success along with Dani King and Joanna Rowsell last week.
And it was Hammer-time for the American, who was beaten on every occasion by the 20-year-old. Trott posted the fastest time of the time trial, whereas Hammer could only manage fourth to relinquish her overall lead.
An ecstatic Trott told the BBC: "I was losing my head a bit in between events. I can't believe it.
"I couldn't ask for much more from the coaching staff. It's all thanks to the coaches.
"Im so happy and i can't thank anyone enough."