British rider Piggy French reflected on "a complete fairytale" after she won the Mitsubishi Motors Badminton Horse Trials and its £100,000 top prize.
In doing so, the Northamptonshire-based rider denied Yorkshireman Oliver Townend a full-scale tilt at eventing's richest prize.
Townend held an advantage of 5.3 penalties heading into Sunday's showjumping finale, but one fence down and four time penalties cost him a second Badminton title 10 years after his first.
It also stalled Townend's hopes of winning eventing's £270,000 Rolex Grand Slam.
It is awarded to any rider that lands consecutive Kentucky, Badminton and Burghley crowns, but has only been achieved twice before - by Britain's Pippa Funnell and Germany's double Olympic champion Michael Jung - and Townend was left to reflect on a near-miss.
French, though, became only the second British winner of Badminton since Townend triumphed in 2009, winning on a score of 26.8 aboard Vanir Kamira.
"I cannot believe it, and I won't believe it for a while. I am numb," she said.
"My whole state of mind was that I woke up first thing and thought maybe I could, but then as soon as I walked the course I thought there was no chance.
"The time was tight, there were so many related distances, and we were definitely getting lower and lower as we went on.
"I kept hearing rattles, but no noise from the crowd, so I thought we must still be there.
"Watching Oliver, I had turned away by the last fence and I thought 'well done him' but then the clock went red. It was very close. It was our day.
"My horse is a pain in the backside for 360 days of the year. She is difficult to manage, but she is amazing and comes to form for Badminton and Burghley.
"If I had built that course at home and practised it in the same-sized arena, I could do it 50 times and never have a clear round.
"But there is something about her. They just do enough when they need to. It is a complete fairytale."
Shropshire-based Townend went into Badminton's showjumping finale as a clear leader aboard his 2017 Burghley champion Ballaghmor Class.
But it proved not to be, as he had to be content with second place - and sixth aboard Cillnabradden Evo - with Australian Chris Burton taking third on Cooley Landis.
"My two horses were amazing all week," Townend said.
"Second doesn't feel as good as first, but it is still very good at this event. The show will keep going."