Natasha Baker's quest for a sixth Paralympic title fell slightly short as she was pushed into silver in the grade III individual dressage at the Equestrian Park in Tokyo.
British rider Baker was grade II champion in London and Rio on Cabral but arrived in Japan with limited competitive experience on current horse Keystone Dawn Chorus, who she only began riding in March 2019.
The 31-year-old competed 10th in a field of 18 and briefly led with her score of 76.324.
But Denmark's Tobias Thorning Joergensen, riding Jolene Hill, swiftly pushed her into second en route to taking the crown with a winning score of 78.971, while Dutch rider Rixt Van Der Horst and her horse Findsley clinched bronze with 75.765.
Baker was pleased with her evening's work.
"The thing that we're lacking is competition experience because we just haven't had the opportunities to go to competitions because of Covid," she said.
"If we were here 12 months ago, I don't think I would have got 76 per cent.
"It's our first competition together like this so that means that next year I can go into the world championships with more confidence and really fight for that gold medal, whereas fighting for the gold medal was never a thing coming here.
"It was just if I win a medal, awesome; I just want to give her a really positive experience."
Great Britain have dominated the sport since it was reintroduced to the Paralympics in 1996.
Silver for Baker, who has permanent nerve damage and weakness in her legs after contracting transverse myelitis at the age of 14 months, was ParalympicsGB's fourth equestrian medal of the current Games.
Sir Lee Pearson won the 12th gold of his distinguished Paralympic career in the grade two event on Thursday, with debutant Georgia Wilson taking bronze, before Sophie Wells added a silver in grade five.
Baker believes she and 10-year-old Dimaggio mare Keystone Dawn Chorus – known as Lottie – are now better placed to compete in Saturday's team test to music.
"All of the top horses in my class have done world championships, European championships," she said.
"They've been into this atmosphere, they've travelled. She went on hunger strike when she was travelling over here.
"It's the first time she's been out of the UK, it's by far the biggest arena she's ever been in and I am just proud of how she's dealt with it. She's just been amazing.
"Everything has been new, it's the first of everything, so I'm just so proud that we were able to go in there and deliver that kind of performance.
"I didn't know how she was going to react, so I just really, really tried to give her a nice time but I think tomorrow I can really go in there and ride her more."
