Sadie won the title at the Westminster Dog Show in New York. Her presentation was overshadowed when two protestors inspired by PETA walked into the center ring at Madison Square Garden. They held up signs that read "Mutts Rule" and "Breeders Kill Shelter Dogs' Chances."
The crowd of 15,000 cheered as security removed the women. Moments later, four-year-old Sadie was placed in the best in show ring.
"I thought it was well-controlled by our people," Westminster spokesman David Frei said, without elaborating. Frei, the host of USA Network's coverage, is a veteran of the show world and a longtime advocate of therapy and rescue dogs.
Sadie was a big favorite coming into the show, which is for 2,500 purebred dogs. There have been previous PETA protests at Westminster, but none nearly so dramatic. During every day of the show, the public-address announcer at the Garden reads an announcement urging people to visit shelters and adopt their dogs.
PETA contends the focus on purebreds leaves many mutts homeless. In a statement, vice president Daphna Nachminovitch said "euthanasia becomes a sad necessity."
Sadie earned her 112th best in show ribbon. The 4-year-old won best in show at the 2009 Chicago Dog Show and appeared on ABC7 News This Morning. The last time a show dog came to Westminster ranked No. 1 in America and actually won was 2001, when a perfectly primped bichon frise called J.R. did it.
"She was perfect," said Sadie's handler, Gabriel Rangel. "I couldn't ask for anything more."
Also reaching the final ring were a brittany that recently had two litters, a whippet that can run 35 mph, a Doberman pinscher headed into retirement, a white toy poodle who overcame his anxiety around crowds, a Canadian-bred French bulldog and a puli that twice won the herding group.
Her tongue out and her tail wagging, Sadie was right in step with Rangel. She is owned by Amelia Musser of Mackinac Island, Mich., and sports the champion's name of Roundtown Mercedes of Maryscot.
Rangel kidded that his relationship with Sadie was like a marriage. "I'm happily married," he said, "as long as I say, 'Yes, honey."'
Sadie became the eighth Scottie to win at Westminster, second most to the 13 wins by wire fox terriers. She was the record 45th terrier to win in a show that began in 1877.
Judge Elliott Weiss picked the winner. He'd already seen Sadie -- he chose her as the winner of an event in North Carolina last September.
Sadie became the first Triple Crown winner of dogdom. She took the National Dog Show in suburban Philadelphia in November and the AKC/Eukanuba National Championship in California in December.
She also did well last year at the world's largest show -- Crufts, in England, draws nearly 25,000 dogs -- when she was judged as the best Scottish terrier.
This was Sadie's third try at Westminster. She got spooked by strange sounds at the Garden two years ago, and last February had a potty accident on the green carpet.
Dogs from 173 breeds and varieties entered this show. Sadie takes over as Westminster champ from Stump, the 10-year-old Sussex spaniel who'd come to New York as an underdog.
Sadie was set to go on the talk-show circuit Wednesday and make a visit to Donald Trump. By night, maybe she'd see herself.
"She likes to watch TV," Rangel said. "We have dinner together at the hotel and watch Animal Planet."
The Associated Press contributed to this report .