History-maker Max Whitlock admitted he had "completely outdone" expectations as he took two gold medals on a vintage day for Team GB with an all-action display of power, control and style.
Golfer Justin Rose and cyclist Jason Kenny added further gloss to a fine day's competition in Rio.
The 23-year-old gymnast followed up becoming the first British male to win an Olympic medal on the floor with a second gold on the pommel horse 75 minutes later.
Earlier this week, he became Team GB's first all-round men's gymnastics medallist since Walter Tysall 108 years earlier by winning a bronze medal on the individual all-around.
He told the BBC: "I've completely outdone myself.
"I never go into competitions expecting to get a medal or even trying to think about it, I go in to do my job.
"For hours and hours in a gym, for years and years - and you get a minute to show it what you've been working on. To do it today, the Olympic Games, I don't know what to say.
"I kind of knew I had to re-focus, I had another job to do. It was very hard to take that (first gold) in, so now I think I'll take them both in at the same time.
"I got emotional after the floor because I wasn't watching any of the routines or anything. It just hit me when I knew what I had done."
His exploits on day nine in Rio - including defeating team-mate Louis Smith on the horse - took Britain's gold medal haul to 13 after Rose edged a tense final round on the sport's return to the Olympics to take the men's individual strokeplay.
Kenny, the 28-year-old reigning Olympic sprint champion beat teammate Callum Skinner to add a 14th gold, while sailor Giles Scott's victory in the men's finn will be confirmed in the medal race on Tuesday.
It meant Britain moved ahead of China into second place on the overall scoreboard, behind only the US.
Kenny's gold in the velodrome took his career tally to five, having won a fourth in the team sprint with Skinner and Phil Hindes on Thursday.
His only defeat in Olympic competition was at the 2008 Beijing Games, when Sir Chris Hoy beat him in the sprint.
Speaking on the BBC, Sir Chris - a six-time champion - said Kenny had the potential "to be the Michael Phelps of the British team".
A gold in his next event, the men's keirin on Tuesday, would take him level with Sir Chris.
Responding, Kenny said: "I will give it my go. We've got a day off now which would be much appreciated - I'm dying on my arse here."
Whitlock's golds sandwiched Rose's historic victory on the golf course.
The 36-year-old from Hampshire narrowly defeated Ryder Cup teammate Henrik Stenson after being neck-and-neck for almost every ball of the final round.
Rose, the world number 12, wrote his name into the history books earlier in the tournament after carding the first ever hole-in-one in Olympic history.
And he took the gold by landing an approach shot within inches of the final pin to leave him with a simple putt for the title.
Speaking after the event, he said: "Today proved to be a great final, and a great final round."
Rose said he decided to sing the national anthem as he took his place on the podium, but could only hear himself.
He said: "Normally you sing it when you're in a stadium with 80,000 people, so I realised how poor my singing is.
"But I muddled through the words. I think I got most of them right. It was just an amazing experience, it really was."
He added: "It's something I've focused on, it's something that I've been hungry for, it's something that I wanted to peak for. It's been at the very forefront of my mind in the last few months for sure."
It was a case of going through the motions for windsurfer Nick Dempsey as Team GB's medal haul continued at a canter on day nine in Rio.
Dempsey, from Weymouth, had already secured the silver medal in the men's RS:X by the time the final race came about, having amassed enough clear water between himself and third-place Piotr Myszka of Poland, but without a chance of catching Dorian van Rijsselberghe in first.
It meant Dempsey, who celebrated his 36th birthday on Saturday, secured a second successive Olympic silver, pipped again by his Dutch competitor.
Dempsey is set to start a new career in photography after the Olympics.