Monty's competition included a bichon frisé called Neal, a Skye terrier named Archer, a whippet and repeat runner-up known as Bourbon and a shih tzu called Comet who's been a finalist before.
The border collie-papillon mix got a round of "app-paws" for her surprise win after finishing the race in under 30 seconds. She is the first mixed-breed and first 12-inch dog to win the competition.
A Barbet, a Biewer terrier, a Belgian Laekenois and a Dogo Argentino are the newest breeds to compete at the 145th show, being held for the first time outside New York City because of the pandemic.