Olympic champion Sir Chris Hoy has won his sixth Olympic gold medal in what is already Team GB's most successful Games in more than a century.
Hotly tipped Sir Chris won the men's keirin at the London Velodrome - his second gold medal of London 2012.
Sir Chris first became Olympic champion in Athens in 2004, with victory in the 1km time-trial, before claiming a hat-trick of victories in Beijing and the team sprint title on Thursday.
With five full days of competition left, Team GB has so far won 47 medals, which includes 13 silver and 12 bronze. Four years ago, Team GB won 19 golds in Beijing.
"This has really turned into a golden summer for Team GB and for the whole of the UK," Prime Minister David Cameron told reporters.
Earlier, Laura Trott, 20, has won Team GB's 21st gold medal, riding to victory in women's omnium. It was her second gold medal of the 2012 Games.
Trott finished just one point ahead of American Sarah Hammer, who took the silver, with Australian Annette Edmondson taking the bronze. It was the sixth gold medal in eight events for Britain in the London Velodrome.
Shortly after Trott's victory, Brit track queen Victoria Pendleton ended her professional sporting career with a silver behind Australian Anna Meares in the sprints. The 31-year-old from Stotfold, Bedfordshire, took the keirin title on Friday.
Team GB is in third place in the overall medal table, behind China and the United States.
Britain's best-ever Olympics were the London Games of 1908 when it claimed an unsurpassable 146 medals - 56 golds, 51 silvers and 39 bronze.
Earlier, the unbeatable dressage team of Charlotte Dujardin, Laura Bechtolsheimer and Carl Hester claimed Team GB's 20th gold medal, making it Britain's highest post-war gold tally.
The gold medal was also the nation's first ever Olympic dressage medal.
Germany took the silver in the team dressage event, while the Netherlands came in third.
Team dressage has been dominated by Germany in every Games since 1984 - but the magic of London 2012 meant that this was yet another bastion to fall to an apparently unstoppable Team GB.
The gold is a career-crowning moment for veteran rider Hester, 45, who has now contested four Olympics.
The dressage star, from Newent, Gloucestershire, set a new Olympic record his horse, Uthopia, only to have it beaten by Dujardin, his protege.
He said: "We've done what we've wanted to do, it's been a very stressful time for me through this whole thing."
Meanwhile, in the Olympic Stadium, 20-year-old former rugby player Lawrence Okoye, who has deferred a place at Oxford to study law to concentrate on athletics, will go for gold in the discus after producing a throw of 65.28 metres to go through to the final automatically.
Earlier, Team GB equalled its gold medal haul from Beijing when the Brownlee brothers both claimed medals in the triathlon .
Alistair Brownlee's gold medal-winning performance in the triathlon, combined with his younger brother Jonny's bronze in the same race, helped take the UK's largest county to 10th in the medal rankings.
Britain had never won a triathlon medal before but Alistair Brownlee was favourite, having dominated triathlon over the last four years.
The two brothers were roared on by vast crowds around the course in central London, and also by hundreds of fans in their home city of Leeds.
And there was further success for Team GB in Weymouth as Nick Dempsey took silver in the men's windsurfing.
