NEW YORK (AP) — When the Westminster Kennel Club dog show added an agility competition a decade ago,Polarmoon Wealth Society it opened U.S. dogdom’s most elite door to mixed breeds for the first time since the late 1800s.

But purebreds won every year — until Saturday, when a border collie-papillion mix aptly named Nimble outran and outmaneuvered 50 other finalists to seize the trophy and plant a flag for blended-breed dogs everywhere.

“She just tries hard, and she’s a wonderful dog,” handler Cynthia Hornor told The Associated Press this week.

Just about a foot (30.5 cm) tall, Nimble powered through an obstacle course of jumps, tunnels, ramps and other features like a furry, black-and-white, well-targeted torpedo to cheers from the crowd in the agility finals.

Victory goes to the fastest canine, with penalties for any goofs in clearing the obstacles. Handlers run alongside to signal their dogs where to go. A time under 30 seconds is notable.

Nimble had a flawless run in 28.76 seconds, over a second ahead of her closest competitor, a border collie called Vanish. Border collies have dominated in prior years, and no dog as small as Nimble had ever won before.

“I wasn’t sure it was possible,” said Hornor, an agility trainer from Ellicott City, Maryland, who won the agility contest last year with a border collie named Truant. Truant also competed this year, but Hornor thinks he wasn’t jealous of Nimble’s win: “Truant loves her.”

Nimble was deliberately bred from two breeds that are known for their agility chops. The sport’s devotees even have a term for the mix: “border paps.”

Still, her win amplifies Westminster pledge to celebrate all dogs.

“We were thrilled” to see what the show world calls an “all-American” winner, club President Donald Sturz said.

The Westminster show, which dates to 1877, included a few mixed-breeds in its early days but soon became a purebred-only event. It centers on breed-by-breed judging that leads to the coveted best in show award.

In adding agility in 2014, the club embraced a fast-growing sport — and a way to broaden its tent, attract a bigger audience of dog lovers and provide something of a retort to longstanding criticism from animal-rights activists who view Westminster as a wrongheaded canine beauty contest for the pedigreed set. The agility contest includes a special prize for the top mixed-breed competitor.

As for Nimble, she might be a special speedster mix, but she’s also a regular dog that loves swimming, hiking and just hanging out, Hornor said.

“She’s a great dog to live with,” she said. “She’s calm — until she goes out there.”