Brock Whiston stormed to her first Paralympic title as Great Britain enjoyed another superb night in the pool with four golds in Paris.
Whiston, 27, came from more than 10 seconds behind at the halfway point to overhaul Alice Tai and secure a much-coveted gold in the SM8 200m individual medley.
Maisie Summers-Newton won her second title of the 2024 Games in the SB6 100m breaststroke, while Grace Harvey upgraded her silver from Tokyo 2020 in the SB5 event.
And to close the evening, the S14 mixed 4x100m freestyle squad were in a class of their own to add to the tally.
Britain now have 16 medals in the pool so far at La Defense Arena, 11 of them gold.
In the 200m individual medley, Tai's 10-second lead was all but wiped out on the third breaststroke leg with Whiston just edging out Viktoriia Ishchiulova in a thrilling freestyle finish, clocking two minutes 40.37 seconds.
British team-mate Tai, who took 100m backstroke gold on Saturday, got the bronze behind the Neutral Paralympic Athlete in 2:41.29 with American 16-time Paralympic champion Jessica Long fourth.
Summers-Newton, 22, led all the way as she retained her 100m breaststroke title in one minute 31.30 seconds, a Paralympic record.
She had already secured gold in the SM6 200m individual medley on Friday.
Harvey, 26, was nearly a second down at 50 metres in her race but fought past China's Zhang Li and Ukrainian Anna Hontar to win in one minute 42.33 seconds.
Of Britain's astounding success, Harvey said: "We are kings and queens in the pool. The team is amazing. Every single individual brings their own uniqueness to the sport, their character, their personality - and the one thing that unites us is our drive."
In the relay, the quartet of William Ellard, Rhys Darbey, Poppy Maskill and Olivia Newman-Baronius - all teenagers - brought GB home ahead of Australia and Brazil.
It was also the second gold of these Paralympics for Ellard and Maskill.
This gold medal has been a long time coming for Whiston, who was unable to compete in the Tokyo Paralympics in 2021 and the 2022 Commonwealth Games in Birmingham because of issues around her eligibility and category.
She started her career in the S8 category, winning four world titles in 2019 in London. Whiston was then moved to the S9 category, where she competed against less-impaired rivals. She considering retiring but, after going through classification again earlier this year, she is back as an S8.
After taking silver in the SB8 100m breaststroke on Friday, Whiston became upset in interviews and spoke about feeling "really disappointed in myself" and believing she had "let everyone down".
Two days later, the emotions were very different.
"I knew I had something to prove to myself and I was out there to show myself what I can do. I was like, 'nothing's stopping me'. I was ready for it tonight," she said.
Asked when she thought she could win, Whiston added: "Actually I never thought I could win it. I just had to go in and swim my race. I said to my coach, 'if I do faster than I did this morning [in the heats] and win any sort of medal, it will be an achievement'. So I'm buzzing."
As a youngster, Whiston was frequently accused of being 'lazy' as she struggled with her co-ordination. She also suffered frequent shoulder dislocations, puzzling doctors before eventually being diagnosed with hemiplegia - which causes weakness and paralysis - on her left-hand side.
Summers-Newton, who has recently completed her degree in primary school teaching, previously told BBC Sport the past three years had been "exhausting", juggling international competitions with her studies.
There did not seem to be any lingering effects as she held off Chinese world record holder Liu Daomin by just under a second, with 14-year-old Ng Cheuk-yan, of Hong Kong, getting the bronze.
Summers-Newton said she felt a lot calmer than before her individual medley final and was "super chuffed" to win again.
"My nerves were on a different planet compared to the IM so I just went in feeling good from this morning's training session," she added.
"My breaststroke is my favourite event. The crowd was amazing, to get another gold medal, defend both my titles, I can't ask for much more."
Grace Harvey was a silver medallist in the SB5 100m breaststroke at the 2023 World Championships in Manchester
Like Summers-Newton, Harvey has combined academia with elite-level sport in recent years, studying for a masters in public dental health at the University of Manchester.
Harvey, who has cerebral palsy and is a wheelchair user, was previously a backstroke specialist and only started racing breaststroke in early 2021.
"It means more than anything," she said. "To say I'm Paralympic champion, I've never dared imagine that I would ever be in this position.
"I knew they were going to go out fast in the first 50 metres and I could see them. I've got a good turn, I've really worked on that and just stuck on my race plan.
"In the final five metres, I was like, 'you want to breathe? Do not breathe. Do not even think about breathing right now because you will regret it for the rest of your life'."
Great Britain won the S14 mixed 4x100m relay in Tokyo in 2021 with a completely different quartet
Day four in the pool ended in style for Britain with Harvey and then the S14 mixed 4x100m freestyle relay squad taking gold in the final two races.
GB sent 200m individual champion Ellard, 18, out first and when Maskill, 19, took over from 17-year-old Darbey at the halfway point, the lead over Brazil was just 0.12 seconds. However, Maskill - who already has a gold and silver in Paris - raced clear.
When she handed over to Newman-Baronius, the gold seemed all but secured and the 17-year-old brought Britain home more than three seconds clear of silver medallists Australia.
"I just tried my hardest to give Olivia a good lead," said Maskill. "It's amazing, we are all pretty young. It's pretty cool for it to be our first time at the Paralympics."
Darbey added: "It's great, one race, one gold. I'm looking forward to seeing what we can do in LA [in 2028]. Everyone in this team is under 20. Hopefully that world record can be ours in LA."
In other finals involving Britons, Callie-Ann Warrington was 0.08 seconds away from a medal in the S10 100m freestyle, finishing fourth in one minute 01.10 seconds as France's Emeline Pierre thrilled the crowd by taking gold in 1:00.49.
Bruce Dee, 17, came fifth in the SB6 100m breaststroke.