Hazel West, 66, from Warwickshire, raised £11,575 for military charity Help for Heroes in order to take part in the eight-mile ride, which started and finished at Ascot racecourse.
The running total raised from the Horses for Heroes event is £386,137.
“I am thrilled to have raised this money for such a wonderful organisation,” said Hazel, who was presented with her trophy after the first horse inspection at Burghley. The award was donated by Berkshire Life magazine.
“The bravery of soldiers returning from the wars in Iraq and Afghanistan is outstanding — they are an example to us all,” she added.
Hazel was inspired to take part in the ride as her husband George, 73, was in the Grenadier Guards. She said she “desperately wanted to do something” to support Help for Heroes and the charity’s “inspirational” founders, Bryn and Emma Parry.
A proud George said: “The generosity of Hazel’s friends was outstanding. She did send out a very personal begging letter, which I think probably helped.”
Hazel agreed, saying: “They certainly did put their money where their mouths are.”
Hazel took part in the ride on her 18-year-old hunter, Henry.
“He enjoyed himself immensely,” she said. “He’s never been to a summer party before — he usually stays in the field until hunting season starts.”