For the third time this week, Great Britain's women's pursuit team set a new world record, this time to claim gold in the velodrome.
Great Britain claimed a third gold medal in as many days in the Olympic Velodrome as their women's team pursuit quartet again lowered the world record with a sensational final display.
The battle for gold between GB and the United States had been much anticipated, after the two teams combined to break the world record on three occasions during qualifying.
However, the US had no answer to their opponents in the final as Laura Trott, Joanna Rowsell Shand, Elinor Barker and Katie Archibald broke new ground with a remarkable time of four minutes and 10.236 seconds, shaving almost two seconds off the previous best.
The silver medallists were ahead early on, but finished 2.218secs back after failing to keep pace when Britain turned up the heat from the 1500m mark.
Trott is the first British woman to win three Olympic golds and could yet earn a fourth in the omnium event.
Canada took bronze in the women's team pursuit, while Saturday's other final saw Elis Ligtlee triumph in the women's keirin, the Dutchwoman edging out Britain's Becky James and Anna Meares of Australia in a thrilling finish.
Meares now has six Olympic medals, gained across four Games.
Four-time gold medallist Jason Kenny will face Callum Skinner in an all-British men's sprint final on Sunday, after both came through their last-four contests.
Defending champion Kenny lost the first race against Russia's Denis Dmitriev, but hit back to book a meeting with Skinner, who defeated Matthew Glaetzer of Australia 2-0.
Trott, Rowsell Shand, Barker and Archibald had already broken the world record in the women's team pursuit on two occasions prior to Saturday's final, but their performance when it mattered most was on another level. The time of the United States would have set a world record on Friday, but they were left trailing in GB's wake.
Prior to Britain's stunning final performance, the women's team pursuit record had been broken twice in Saturday's semi-finals, by the US and Team GB. Britain had also lowered the same mark in Thursday's qualifiers.
QUOTES OF THE DAY
"I've never been in a team that feels so seamless. I actually said to Kate [Archibald], 'that was possibly the easiest world record we've ever got'," - Trott was amazed by Great Britain's time in the women's team pursuit final.
"The semi-final didn't go as I had hoped, but in the keirin, anything can happen. In the final, I raced on intuition. I came from the back, so I had to make two sprints, one to move up, and another in the end. I know I can make a long sprint. And now I am Olympic champion. It's unbelievable," - Keirin champion Ligtlee delights in her victory.