Lee Pearson and Debbie Criddle added two more golds to Britain's equestrian medal haul with victories in their dressage events on Thursday.
Pearson scored a whopping 87% on Blue Circle Boy to comfortably win the grade I individual freestyle.
Criddle then doubled the tally aboard Figaro IX in the grade III competition with a score of 81.722%.
It was both riders' second gold of the Games, having won the individual dressage events earlier in the week.
Pearson, 30, finished more than 10 points ahead of his nearest competitor.
He won a hat-trick of golds at the Sydney Games in 2000 and could repeat his remarkable feat if Great Britain retain the dressage team event title on Sunday.
"I used the horse's power to the maximum, but it could have gone either way," he said.
"The judges could have felt that it was too spectacular, but they just sat back and enjoyed it.
"I'm so over the moon with the way my horse behaved - I don't think I've ever got higher marks than 85% before.
"This feels different to Sydney, but just as good. Here I was riding my own horse that I have trained from a baby - we did it together, and that makes it special."
Criddle, who finished nearly four points ahead of second-placed rider Bettina Eistel of Germany, was also impressed with her win.
"I am really surprised with the marks I have been given," she said. "They are very high but this is not a personal best for me.
"I have reached 84% in the European Championships in Portugal two years ago."
British team-mates Anne Dunham and Sophie Christiansen finished just out of the medals in fourth and fifth in the grade I event with Pearson.
It was a disappointing result for the two riders, who had been leading for most of the morning.