Stevens, who first competed at the level in 2007, previously rode Chilli Knight’s mother, King’s Gem.
“It’s unbelievable, I’ve known him [Chilli Knight] since the day he was born and this honestly means the absolute world,” she said.
The win is redemption for Stevens after a disappointing World Championships in Aachen, Germany last month, when she failed to complete the cross-county event for the British team.
“Aachen was really tough, but that’s sport. You’ve got to just bounce back and get on with it,” she added.
Stevens and Chilli Knight previously won the replacement five-star event at Bicton in 2021, after Covid cancelled Burghley.