Charlotte Fry won bronze in the dressage individual grand prix on Sunday, adding to the team bronze Britain won on Saturday.
Fry, riding Glamourdale, scored an impressive 88.971% to clinch third in a competitive field, behind Germans Jessica von Bredow-Werndl who won gold and Isabell Werth who claimed silver.
"I'm speechless. It's absolutely amazing. I'm so, so proud of Glamourdale. I 100% knew he was capable of it, but to be able to pull it off today and get the bronze, it's just incredible," Fry said.
"The support from the crowd was amazing. The prize giving was just insane. That feeling going around with Jessica [Von Bredow-Werndl] and Isabell [Werth] too, idols and huge inspirations in our sport, it was just incredible.
"To get the team bronze yesterday, it was an amazing feeling. I feel like it was so well deserved with the three of us, then to get the individual medal was crazy.
"I think you always dream of it. I always am striving to be better and I know Glamourdale is one of the best horses in the world, so I knew it was possible."
Making her 17-year-old mare Dalera dance with elevated passage trots and rhythmic flying changes to a medley of Edith Piaf's greatest hits, von Bredow-Werndl reached an overall score of 90.09%.
Since her Tokyo debut, von Bredow-Werndl, 38, has finished the four Olympic dressage contests she has taken part in with a gold medal, pocketing the two individual titles and being in the winning teams at the two Games.
Briton Carl Hester and Fame held the lead early on with a score of 85.161% before falling to sixth. Becky Moody and Jagerbomb also performed well, scoring 84.357% and finishing in eighth.
Dinja van Liere, riding Hermes, was fourth while Denmark's Cathrine Laudrup-Dufour -- seen as one of the hottest contenders for the final after getting the best marks in the qualification and team events -- came in fifth.
Information from Reuters contributed to this report.