Pentathlete Joe Choong won Great Britain's 20th gold medal of the Tokyo Games after boxer Galal Yafai became an Olympic flyweight champion on Saturday.
Choong followed Kate French's victory on Friday in the women's event by becoming the first British man to win individual modern pentathlon gold.
Josh Kerr in the 1500m and diver Tom Daley won bronzes, with silver for cyclists Matt Walls and Ethan Hayter.
Team GB remain fourth in the medal table on the penultimate day.
They have won 62 medals in total and have one more gold than the Russian Olympic Committee in fifth, with sixth-placed Australia a further two behind.
Daley's bronze in the men's 10m platform was his second medal in Tokyo and came two hours after Yafai won his gold.
Walls, the men's omnium champion in Tokyo, collected another medal in the velodrome - this time alongside madison partner Hayter.
Kerr claimed Britain's first men's Olympic 1500m medal since Peter Elliott's silver in Seoul 33 years ago.
The United States' victory in the 4x400m women's relay meant Allyson Felix is now the nation's most decorated track and field athlete, an 11th Olympic medal taking her past sprint and long jump great Carl Lewis.
Clean sweep in the pentathlon
Maybe it was written in the stars for Choong as he powered to a historic modern pentathlon triumph.
The 2019 world champion led going into the fourth event, equestrian, where riders are randomly paired with horses, and he drew Clntino, just as French had on Friday.
Choong maintained his lead, and kept his composure in the final laser run to seal a memorable GB double.
"To be honest, I just didn't want Kate to have all the limelight," joked the 26-year-old from Kent, who was 10th at Rio 2016.
"I've always said I wanted to be the best in the world. This is literally a dream come true.
"I pulled myself together and this time I've nailed it."
Double delight for Daley
At Rio 2016, Daley was heartbroken after bombing out of the men's 10m platform semi-finals.
Five years later, he qualified fourth for the final in Tokyo behind Chinese pair Cao Yuan and Yang Jian, and Aleksandr Bondar of the Russian Olympic Committee.
The 27-year-old, who won gold in the synchronised event with Matty Lee, led the competition through the halfway point and was guaranteed his second medal of the Games after his final attempt, with the trio who finished above him in the semi-finals still to dive.
Bondar was too far behind to challenge, and though Cao and Yang took gold and silver respectively, Daley wrote his name in the history books as the first British diver to secure four Olympic medals.
Daley reached two finals on his Olympic debut, aged 13, at the 2008 Games and won his first Olympic medal at London 2012 - a bronze in the 10m platform.
Four years later, it was another bronze, this time in the synchronised event alongside Daniel Goodfellow.
Twice an individual world champion, Daley finally ended a long wait for Olympic gold alongside Lee in an emotional and nerve-filled men's synchronised 10m platform final last week.
Second time lucky for Yafai
Former car factory worker Yafai was determined to persevere with his Olympic dream after his defeat by Cuba's Joahnys Argilagos in the second round at Rio 2016.
Since then, the 28-year-old has enjoyed a steady stream of medals, winning silver at the 2017 Europeans, gold at the 2018 Commonwealths and bronze at the 2019 European Games.
The Birmingham fighter, whose brothers Gamal and Kal are both professional boxers, claimed his biggest title of all and Great Britain's fifth boxing medal of a guaranteed six in Tokyo with a 4-1 points decision victory over Paalam at the Kokugikan Arena.
Bronze medals have already been secured by Kariss Artingstall and Frazer Clarke, while Pat McCormack and Ben Whittaker won silver.
With Lauren Price guaranteed at least a silver and GB's sixth boxing medal of the Games in Sunday's middleweight final, Tokyo 2020 will be Britain's most successful Olympics in the boxing ring since 1920.
Walls and Hayter add second madison medal
Matt Walls and Ethan Hayter looked to be battling for bronze before a break in the closing stages gave them silverMatt Walls and Ethan Hayter's madison silver marks a sixth medal on the cycling track for Team GB in Tokyo - more than any other nation.
Walls, 23, has finished on the podium for the second time on his Olympic debut after taking gold in Friday's omnium, while their efforts produced a second madison medal in two days, after Laura Kenny and Katie Archibald's dominant gold-medal ride on Friday.
Walls and Hayter held the gold medal spot after 10 sprints, having made a strong and consistent start but faded in an open race before a breathless final sprint secured silver.
It was still not enough to overhaul reigning world champions Denmark, who won gold, with France third.
What else has happened on Saturday?
