Ellie Simmonds claimed her fourth medal of London 2012 when she took silver in the S6 100 metres freestyle.
The 17-year-old had already secured two golds and one bronze and qualified second for the two-length race.
She repeated that in the evening session when she touched second after Victoria Arlen in one minute 14.82 seconds with the American lowering her own world record to 1min 13.33secs.
Simmonds told Channel 4: "I gave it everything on that last 50. I could see her but I just didn't have anything left.
"I'm just really chuffed. A PB by over a second, I'm just really happy. I would have loved to get the gold but you can't have everything."
Asked how the Games compared to 2008, she said: "I think Beijing's always going to be the best Games for me. I loved it all and it was my first Games.
"This Games has been amazing as well though. It's been topped off by my swims.
"It's been really good in front of a home crowd, it's been amazing.
"I don't want it to end but it is ending and I'm just looking forward to celebrating now.
"I'm just going to celebrate with the team and be with them and enjoy it all."