UPPERVILLE, Va. — Genuine Risk, one of only three fillies to win the Kentucky Derby, died today at Newstead Farm.

The 1980 Derby winner died peacefully about 7:30 a.m. at the advanced age of 31 after eating a hearty breakfast and being turned out in her paddock, an office administrator at the farm, Cindy Perry, said. Ms. Perry said the filly had not been ill.

Genuine Risk was the oldest living Derby winner, and the only filly to finish in the top three in each of the Triple Crown races. She was second in both the Preakness and the Belmont Stakes.

“Genuine Risk was an amazing horse with tremendous heart that lived a life befitting a champion,” owners Bertram and Diane Firestone said in a statement issued by the farm. “We are truly blessed that she was a part of our life and we are deeply saddened by her passing.”

It was in the 1980 Derby where Genuine Risk made history, taking a commanding lead in the stretch of the 106th Derby and outrunning Rumbo and Jaklin Klugman for the victory. She paid $26.80 to win and immediately became one of the top fillies in racing history.

Purchased for $32,000 by the Firestones at the request of their 14-year-old son, Matthew, in July 1978, Genuine Risk was trained by a Hall of Famer who five years earlier guided Foolish Pleasure to victory in the Derby, Leroy Jolley.

At 2, Genuine Risk raced four times and won them all, including a pair of stakes races in New York, creating a buzz about her potential to race against 3-year-old colts.

Only four years earlier, the women’s liberation movement had even come to the racing world, but with tragic results. In a televised match race between the speedy filly Ruffian and Foolish Pleasure, Ruffian broke her leg and had to be destroyed at Belmont Park.

Mr. Jolley was not inclined to race Genuine Risk against colts, but when she began her 3-year-old campaign with easy victories against other fillies, and when there seemed no clearcut favorite for the Derby, Firestone’s desire to test Genuine Risk prevailed.

Running in the Wood Memorial, a New York race that typically helps owners and trainers measure their horse’s fitness for the Derby, Genuine Risk ran third, a finish that Firestone was convinced could be improved on with more training by Mr. Jolley.

When she ran in the Derby, Genuine Risk became the first filly to enter the race since 1959, and when she withstood stretch challenges from Jaklin Klugman and Rumbo and won, she became the first filly to wear the roses since Regret in 1915. The only other Derby winning filly was Winning Colors in 1988.

Even more impressive, she ran the last quarter-mile faster than any Kentucky Derby winner except Secretariat, a Virginia-born colt and the 1973 Triple Crown winner.

After running second in the Preakness and the Belmont, she went on to a 4-year-old campaign with three starts — winning twice and running third.

Genuine Risk won 10 of 15 career starts, with three seconds and two thirds.

The filly was retired in 1981 for an anticipated life of producing winning offspring. She was even bred to Secretariat with great anticipation in the racing world in 1982, but delivered a stillborn foal in 1983, the first of her numerous breeding failures.

It took 11 years for Genuine Risk to produce a live offspring, which appropriately was named Genuine Reward, but the horse never raced and went immediately to a stud farm.