One For The Road, a 14-year-old chestnut gelding who was well-known to riders and owners on the horse show circuit, collapsed and died yesterday after showing in an amateur-owner jumper class at the Washington International Horse Show.

Officials said it was the show's first equine death since moving to Capital Centre eight years ago.

Better known by his barn name, "Frankie," the horse had just competed in a timed jump-off round with owner Paula Inman of Farmington Hills, Minn., in the saddle. The gelding, who had the best clocking of nearly 30 entries but finished out of the money with four faults, was being returned to his stable in the parking lot when he "collapsed and was dead within 30 seconds," according to show veterinarian Stephen Soule.

Soule said the horse died from a stroke or heart attack. The Maryland Department of Agriculture will perform an autopsy.

Inman, 20, said no drugs had been administered to her horse.

Described as "a Cinderella horse," One For The Road had several owners, including actress Linda Blair, and had been turned into a jumper in the last three years, winning the $2,000 Insilco Jumper Classic in Harrisburg last week.

Dalfsen, a 7-year-old bay ridden by Anne Kursinski, bested a talented field of 32 entries to win the $5,000 International-Open jumper for the Inverness Farm Challenge Trophy.

Kursinski, 24, from Pasadena, Calif., rode the stallion in a clean first round over 11 obstacles and returned with 13 other entries, all from the United States, for a timed test over seven jumps. This time they were perfect in 24.28 seconds. George Morris of Pittstown, N.J., rode Fortuna to second place in 25.88 seconds, with Buddy Brown in third place at 25.97 seconds aboard Eclair de l'Ile.

The Governor, owned by Mrs. Averill Harriman and ridden by Katie Monahan of Upperville, Va., was named Intermediate Jumper champion with eight points. Reserve went to Madrano, ridden by Kursinski, with six points.

Super Flash, ridden by Charlie Weaver, was named champion in the Regular Working Hunter division with 11 points. Reserve champion was Emily Post, with nine points.

Barney Ward, aboard the 8-year-old Oldenberg gelding McLain he has ridden three times since buying him three weeks ago, was again the evening star of the show with a 1,070-point ride in the $5,000 Gambler's Choice international-open event.

Ward, 43, a former semipro football player from Brewster, N.Y., rode McLain over an obstacle course whose fences were rated at different point values. Entries jump as many fences as 40 seconds allow.

"You want a horse that can jump clean," said Ward. "He's a very clean jumper. I didn't think I'd do that well with him. I didn't think he was that fast. It's a really tough course."

McLain never missed a fence and twice cleared the tall Joker fence, a vertical jump where the top rail is easily tipped. Clean jumps were worth 200 points, the highest on the course, but, unlike other obstacles, errors at the Joker cost 200 points. The winning ride gave Ward the edge in the race for leading national rider with 18 points.

Linky, ridden by Tim Grubb, was close behind in second place with 980 points and The Performer, with Brown, of North Smithfield, R.I., was third with 950. Ferner, ridden by Ward's riding student, Alexa Bell, finished fourth with 920 points.

In tonight's puissance, Ward will defend his North American indoor high jump record of 7 feet 6 3/4 inches, set last year aboard Glandor Akai.

The U.S. team easily retained its lead in the international standings with 61 points, followed by Canada with 23 and West Germany with 13.

In national rider standings, Kursinski trails Ward with 14 points. Grubb of Summit, N.J., has 13 and Morris has 12.