World champion Anna Meares made an early move as soon as the pace-setting bike went off the track, but Victoria Pendleton accelerated from one-and-a-half laps to go and took to the front before sensationally pulling away to claim her second Olympic gold.
Meares, of Australia, finished in fifth place.
Hollywood actor Samuel L Jackson has a new-found admiration for British cycling, and we've got the tweets to prove it.
Great Britain has won another gold medal in cycling. Victoria Pendleton rode to glory in the women's keirin.