Laura Trott, Dani King and Elinor Barker swept aside Australia in the women's team pursuit final to hand Great Britain their first gold medal of the Track Cycling World Championships in Minsk.
The victory was Britain's fifth in the six years that the event has been held and was the third in a row for Trott and King.
It was also Britain's second medal of the afternoon and fourth of the championships, after Becky James claimed her second bronze medal in as many days with an impressive third place in the women's 500m individual time trial.
But the day's best performance came from Ireland's Martyn Irvine, who claimed silver in the men's individual pursuit and then, just an hour later, won a sensational gold medal in the scratch race after a late solo attack.
Britain's Owain Doull, 19, finished fifth in the scratch race after a mature and well-measured performance in his debut World Championships.
The most fervent British celebrations, though, were saved for Trott, King and Barker, who booked their place in the team pursuit gold-medal final by qualifying more than two seconds faster than the rest of the field in Thursday's morning session.
They trailed Australia by 0.3 seconds after the first kilometre of the final, but soon began to up the pace and had powered into a 0.8secs lead by the 2km mark.
They continued to turn the screw in the final four laps and crossed the line in 3:18.140, 1.77secs in front of the well-beaten Australians.
Trott said afterwards: "It was really hard. It seemed to flow really nicely, which was good. We changed a few things from qualification to make it a bit smoother and easier in the final and it paid off. It came together really nicely."
Worlds debutante Barker added: "I feel really overwhelmed at the moment. A couple of months ago, if you had said I would have been in this team, I would have been like, 'No'. I can't believe I have won. It's not sinking in at all. I just feel shocked."
Becky's bronze double
Earlier in the session, 21-year-old James, who won team sprint bronze alongside Vicky Williamson on Wednesday, was the first of 12 riders out on track in the 500m time trial and set an imposing time of 34.133 seconds, knocking 0.6secs off her personal best.
It took until the third-last competitor to better that mark, with Wai Sze Lee's 33.973 proving enough to earn the gold medal.
That left James in the silver medal position with just Miriam Welte to go, but the German bettered the Briton's time by just over 0.1secs to push her down into third.
James was nevertheless delighted with the result. "I didn't think I was going to be on the podium," she said. "It got a bit agonising before the end, but I am so chuffed.
"I wasn't sure how it was going to go today because it is probably my least favourite event, but I left everything out on the track and [it is] another success for GB, so I can't complain with that."
Williamson was also in the race, finishing 11th in a personal-best time of 35.409.
James will now recuperate before mounting her bid to win a third medal of the championships in her favourite event, the individual sprint, which starts on Friday and concludes on Saturday.
In the day's other medal race, Germany beat New Zealand to gold in the final of the men's sprint, with France overcoming Australia to claim bronze.
Irvine was beaten in the men's individual pursuit gold-medal race by Australia's Michael Hepburn.