Maisie Summers-Newton claimed her second gold of the Tokyo Games following a Paralympic record and lifetime best time in the SB6 100m breaststroke final.
The 19-year-old's performance of 1:32.34 clinched the title ahead of China's Daomin Liu and American Sophia Herzog.
Fellow ParalympicsGB athlete and Summers-Newton's idol - Ellie Simmonds - missed a podium place after finishing fourth, 7.6 seconds off the pace.
Summers-Newton, who is performing at her first Paralympic Games, picked up her maiden Paralympic gold on Thursday after winning the SM6 200m individual medley.
The Northampton swimmer has admitted that her successes have exceeded, even her own, expectations.
"I'd hoped for the first one in the individual medley but to get two, it's just what dreams are made of isn't it, really?
"Just incredible obviously, I have no words. I don't think this one has sunk in as much as the medley because I really, really wanted it, so this one is just the icing on the cake definitely."
Summers-Newton and Simmonds are set to compete together again in the S6 400m freestyle on Thursday.
Asked how her more experienced team-mate is, Summers-Newton replied: "Oh yeah, she's fine.
"I think Ellie's here - I don't want to speak on behalf of her - but I think obviously she's here for her fourth Games just to really enjoy it and just to be with the team. I think that's what everyone aims for.
"She's inspired people like me and I'm sure all the other athletes here."
Team gold and individual silver for ParalympicsGB
Reece Dunn, Bethany Firth, Jessica-Jane Applegate and Jordan Catchpole also produced a golden performance on Saturday in Tokyo as they won the mixed 4x100m freestyle relay S14 title.
The quartet stunned the rest of the field with a world-record time of 3:40.63 and finished over five seconds faster than their closest rivals - Australia. The bronze medal was won by Brazil, who were 10 seconds slower than ParalympicsGB's team.
Meanwhile, Grace Harvey won silver in the women's 100m breaststroke SB5.
Harvey, who first took up swimming as a form of physiotherapy to help control spasms in her legs caused by cerebral palsy, was inspired to compete after watching the 2004 Paralympic Games.
This Paralympic Games marks her debut. Harvey's time of 1:42.22 kept Germany's Verena Schott at bay, but wasn't quite fast enough to overcome Yelyzaveta Mereshko on the day.