The women's team pursuit world record was smashed for the third time in a day as Team GB retained their Olympic title in sensational fashion and Laura Trott became the first British female to win three golds.
Earlier on Saturday, Team GB saw the record time they set on Thursday lowered by nearly a full second by the USA, only to take it back a matter of minutes later.
In the final only one of them could break the record again and it was the Brits who did so by two full seconds, to take the mark down to 4.10.236 and take the gold - a particularly historic one for Trott.
She said: “We broke the world record in training, doing a 4.13.00 in our holding camp in Newport. We knew a WR was on the cards in the qualifier. It felt surreal in the qualifier, but in the second round it just felt easy. I didn’t believe we were going to do it.
“To come out and do that again today. [Endurance coach] Paul Manning said to us four years ago that 4.10.00 would win the Olympics and we were doing 4.21.00 at that time – that’s a second a lap!"
The gold, and the world record, mirrors GB's win at London 2012 in the event, which then was only contested over 3000m. In that event, the British riders set a world record in every round on their way to the gold, which was the case again in Rio.
As Trott, Joanna Rowsell Shand, Katie Archibald and Elinor Barker were still coming to terms with their Olympic gold, Becky James claimed a silver medal in the keirin, narrowly missing out on Britain's fourth gold of the Games on the track.
Having missed much of the last three years with injury, having won the 2013 World Championships in the discipline, James was delighted to come away with a medal.
"I can't even believe that happened. I am over the moon. I feel like I am in really good form and it is what I needed," she said.
"I love the keirin and I love the racing. Through the first round today I thought I am just going to enjoy the whole day of bracing and after the back straight I kept thinking when do I go. I had so much speed in that last half, I don't know where it came from. I just went for that medal."
Britain are also guaranteed gold and silver in the men's individual sprint final on Sunday afternoon, after Callum Skinner and Jason Kenny won their respective semi-finals.
Skinner only needed two races to beat Australia's Matthew Glaetzer, while Kenny required a third race to overcome Russia's Denis Dmitriev.
"Jason slipped up on one occasion against Dmitriev in that first round and he learned his lesson there," said head coach Iain Dyer.
“But when you come to a new track and a new venue where you’ve not had the chance to have a proper competition on it you’ve got to learn pretty fast.
“In the early rounds you saw fantastic form and speeds from those guys. Today you saw race-craft and it’s just those two boys against each other now. It’s a fantastic position to be in."