LEXINGTON, Ky. (AP) -Personal Ensign, who capped her brilliant unbeaten career with a thrilling victory in the 1988 Breeders' Cup Distaff, has died. She was 26.

Claiborne Farm stallion manager Bernie Sams said Personal Ensign appeared to die of natural causes. Her body was discovered in a field for retired broodmares Thursday morning.

Owned by Ogden Phipps and trained by Hall of Famer Shug McGaughey, Personal Ensign became a sensation during her spectacular career. She won eight Grade 1 races between 1986-88, including six during her 4-year-old campaign alone.

``Personal Ensign was the first Breeders' Cup winner for my grandfather and for Shug and she was just a very special horse to everyone in our family,'' said Daisy Phipps Pulito. ``It's a very sad day for all of us.''

Notable victories included the 1988 Whitney Handicap at Saratoga - when she beat a field of boys by 1 1/2 lengths - as well as the Maskette Stakes and the Shuvee Handicap.

Not bad for a horse whose racing career appeared to be in jeopardy after suffering a severe injury to her left rear pastern while preparing for the 1986 Breeders' Cup. McGaughey thought at the time his prized filly was destined to become a broodmare and nothing more.

Doctors placed five screws in her left rear ankle to stabilize the joint, and after an 11-month layoff she returned to become arguably the sport's biggest star.

McGaughey called her ``a career-maker,'' though he refused to take credit for her success. The way he figures it, he was simply along for the ride.

``Obviously she was very talented and she had a big will to win,'' said McGaughey on Friday at Keeneland Race Course.

One who had a flair for the dramatic.

Pitted against Kentucky Derby-winning filly Winning Colors in the '88 Breeders' Cup Distaff at Churchill Downs, Personal Ensign trailed by five lengths at the top of the stretch. McGaughey thought the unbeaten streak was over.

``I didn't think she was going to win,'' he said. ``She never got in the right position and she was struggling with the race track. Winning Colors was on an easy lead.''

Then came a charge for the ages. Personal Ensign tracked down the Derby winner in the final yards to win by a nose and finish unbeaten in 13 career starts while earning more than $1.6 million.

``She's determined,'' jockey Randy Romero said after the race. ``There's a one in a million you can get like her and she's the one. What's so good about her is she doesn't want to get beat.''

Nobody ever did, though her 13-0 mark has been eclipsed by star mare Zenyatta, who entered Friday's Apple Blossom at Oaklawn Park unbeaten in 15 races.

Zenyatta's run at Personal Ensign's record brought McGaughey's star back into the spotlight. But he says there is no rivalry between the two camps. In his mind he thinks there's room enough in history for both.

``I pull for Zenyatta,'' he said. ``I was pulling for her when she went for 13. I was pulling for her when she went for 14 and 15 and I'm pulling for her today.''

Personal Ensign, voted into racing's Hall of Fame in 1993, was retired to Claiborne in Paris, Ky., after winning the Distaff and became one of the most successful broodmares in racing. She was chosen Broodmare of the Year in 1996 before being pensioned in 2007.

Offspring include Grade 1 winners Miner's Mark, who won the 1993 Jockey Club Gold Cup and My Flag, who captured the 1995 Breeders' Cup Juvenile Fillies.

She was buried at Marchmont Cemetery alongside stablemates Easy Goer, Private Account, Numbered Account and Relaxing.