Great Britain have won men’s team pursuit gold - giving Sir Bradley Wiggins a fifth Olympic gold and a British record eighth medal in all.
It was also a third gold for Yorkshireman Ed Clancy, following the team pursuit titles he contributed to in Beijing, London and now Rio.
He also won a bronze in the omnium at London 2012.
Clancy – who was born in Barnsley, raised in Huddersfield – Steven Burke, Owain Doull and Wiggins clocked a world record of three minutes 50.570 seconds in the first round of the four-man, four-kilometres event.
Australia advanced to the final while keeping Jack Bobridge in reserve, having so far not shown their full hand.
And the perennial rivals - Australia won March’s world title ahead of Britain - slugged it out for gold.
Britain were trailing until 500m to go, when a huge roar erupted from the numerous Britons in the crowd.
And Britain surged on to win gold in a world record of 3mins 50.265secs.
Australia’s Alex Edmondson, Michael Hepburn, Sam Welsford and Bobridge clocked 3mins 51.008secs.
It was Britain’s third straight Olympic title in the event, which Wiggins and Clancy also won at the 2008 Games in Beijing.
Bronze went to Denmark ahead of New Zealand.
Britain beat their own world record - of 3:51.659 set in winning gold at London 2012 - in the first round, effectively a semi-final, which took place 80 minutes prior to the final.
There were reports that Britain and Australia had clocked unofficial world records in training in the last 18 months and it appeared Australia had been bluffing in the first two rounds.
Australia set off faster and kept Britain at bay, but lost a rider before the 3km mark.
Burke peeled off with under two laps to go, once Britain were ahead, and Wiggins took to the front.
So powerful was his surge that Wiggins distanced Doull.
Three riders must cross the line to record a time and Doull clung on as Britain triumphed by 0.743.
“It’s the best of them all,” said Clancy, the only man to have been in this team for their wins in 2008, 2012 and 2016.
“Truth be told we haven’t won a fat deal between London and now. We have had some big downs but crossing the line, a second ahead of the Aussies made every single pedal rev and every single training session worthwhile.
“We have been through the mill a bit and one of the first people to see me was our team doctor. The medical team have put about a thousand man hours into my back, to get me where I am now – I can’t thank those guys enough.”
Wiggins said: “Really the last 12 months we’ve pretty much done everything together, training camps at altitude, early-morning starts at the track, late finishes at the track before Christmas Day, all for this.
“And we’re here and we’ve done it. These four guys here - I would never have come back if we didn’t have the calibre.
“I’ve always said Ed and Burkey, for me, are two of the most underrated athletes I’ve ever raced with.
“They’re so talented and they don’t get the credit for it because theyre not big road stars
“Then you’ve got Doully who reminds me of a young G (Geraint Thomas). Can do anything in the sport and nothing fazes him, especially Olympic finals at 21.
“When you’re with guys like that on the line it makes your job a hell of a lot easier
“In some ways I realised what we were going into and that adds nerves to it.
“These guys were bouncing off the ceiling all afternoon.
“But I kept it all in check. One step at a time, not thinking about the gold.
“And that’s hard when all our team-mates are winning golds in front of you.
“Just fantastic... fantastic.”
Britain advanced from Thursday’s qualifying session in first place and met fourth-placed qualifiers New Zealand in the first round.
The Kiwi quartet finished in 3:55.654 - perhaps reigniting Mark Cavendish’s argument that he could have been included in the line-up.
Cavendish, who is chasing a first Olympic medal, knew the team pursuit represented a surer chance of success than the six-discipline omnium for which he has been selected.
The 31-year-old Manxman, the reserve rider for the team pursuit, completed a training session earlier on Friday and was not present when Wiggins and company arrived at the velodrome.
Reserve riders usually warm-up with the team, in case of a late illness or injury, but changes are not permitted an hour before competition.
Cavendish’s absence could point to tension in the ranks, although there were reports he was heading to the velodrome to watch his team-mates.
He wrote on Twitter: “Some reports that I’m refusing to warmup tonight at the velodrome A bit early when I’m racing Sunday! Good luck to my teammates! Smash it!”
Earlier this week Cavendish said he would not be used in the event, suggesting Wiggins had frozen him out and was “super stressed”.
British Cycling denied suggestions of friction between Wiggins and Cavendish, who is competing in his third Olympics pursuing one glaring omission from a glittering CV which features 30 Tour de France stage wins, the 2011 world road race title and three Madison world titles on the track.
Cavendish’s two-day omnium campaign begins on Sunday and concludes on Monday. He was sixth at March’s Track World Championships in an event which is something of a lottery.
Cavendish will be coached by Rod Ellingworth, his long-time mentor and the British road coach, on the track.
Ellingworth will be working as a track coach for the first time since 2009, when Cavendish made his most recent Track World Championships appearance prior to this year.
The return of Ellingworth has led to a suggestions of a falling out between Cavendish and Heiko Salzwedel.
Jason Kenny and Callum Skinner, team sprint gold medallists on day one with Phil Hindes, made a supreme start to the sprint competition.
The pair qualified in first and second place, meaning they could meet in Sunday’s final.
Beginning his bid for a fifth Olympic gold, Kenny beat Germany’s Maximilian Levy in the first round and Skinner deposed of Patrick Constable of Australia.
Kenny won gold at London 2012 after winning a selection battle with Sir Chris Hoy, but the event has been expanded, with two riders per nation permitted.
There is a long day of sprint competition on Saturday, with only the finals taking place on Sunday. Kenny will meet Fabian Puerta of Colombia in the second round, while Skinner will meet Constable, again, after the Australian advanced in the first-round repechage.
Britain did not qualify for the first event of day two, the women’s team sprint, a turn of events which ultimately led to the resignation of technical director Shane Sutton amid discrimination allegations which he denies.
China won gold ahead of Russia, with Germany taking bronze ahead of Australia.