Mr. Stewart's Cheshire Foxhounds of Unionville, Pa., continued to dominate Hunt Night competition at the Washington International Horse Show last night at Capital Centre. It was the team's second straight title and third in four years.

The Farmington Hunt of Charlottesville, originally counted out of the grand honors due to a mathematical error, ended as reserve grand champion, one point behind the winning 22. The Goshen Hounds team of Olney was set back to third.

Mr. Stewart's Cheshire Foxhounds, the most successful hunt at this show with six previous victories in the last two decades, included Amadeus, Manotazso, Irish Whiskey, Samuel Gwiffy, Toi Tai and Snowy River, ridden respectively by Jack Trainor, Nancy Miller, Joy Carrier, Buck Davidson, Nancy Davidson and Bruce Davidson.

The Farmington Hunt consists of Grolosh, Someday Soon, Quaker Hill Beth, Freeway, Alescart and Free Booter and their respective riders, Elizabeth Lower, Paula Falk, Paige Scheibel, Tom Bishop, Ellie Wood Baxter and Pat Butterfield.

Freeway, ridden by Tom Bishop and owned by The Barracks of the Farmington Hunt, won the masters class. First Choice and rider Laurel Pickett won the ladies hunter hack for owner Jean Frost and the Goshen Hounds. Hey Sailor, ridden by William Howard and owned by Pink House Stables of the Aiken Hounds of South Carolina, won the gentlemen's hunter hack and the field hunter 30-and-under division. Snowy River, ridden by Bruce Davidson and owned by Ite Young, won the field hunter over-30 division for Mr. Stewart's Cheshire Hounds.

Tonight's events include the International Hunter Futurity championship and International Open Jumpers.

Davidson, of Unionville, Pa., a two-time world champion and two-time Olympic champion three-day eventer, has not been known for his proficiency in fox hunting competition. The teams showed over a course of fences designed to simulate a fox chase. The teams were judged on performance, suitability, manners, soundness and team uniformity.RESULTS

Hunt Night Grand Champion: Mr. Stewart's Cheshire Foxhounds, Unionville, Pa, 22 points. Reserve Grand Champion: Farmington Hunt, Charlottesville, 21. Third place: Goshen Hounds, Olney, Md., 16.

Masters Hunt Class: (horse, owner/hunt team, rider): Freeway, The Barracks/Farmington Hunt, Tom Bishop; The Alderman, Mary Robertson/Deep Run Hunt, Mary Robertson; Brigadoon, Hardy Pickett/Goshen Hounds, Brian Pickett; Cinzano, R.D. Rouse/Fairfax Hunt, Mary Francis Smoak.

Gentlemen's Hack Class: Hey Sailor, Pink House Stables/Aiken Hounds, William Howard; Pearl of the Orient, Hardy Pickett/Goshen Hunt, Hardy Pickett; Full Odds, Denise Esbenshade/Mr. Stewart's Cheshire Foxhounds, Jack Trainor.

Ladies Hack Class: First Choice, Jean Frost/Goshen Hounds, Laurel Pickett; Court Call, The Barracks/Farmington Hunt, Meredith McLaughlin; Richard, J. Berk Lee/Orange County Hunt, J. Berk Lee.

Field Hunter 30 and Under: Hey Sailor, Pink House Stables/Aiken Hounds, William Howard; Cub Scout, E. Sue Smith/Casanova Hunt, E. Sue Smith; Grolish, Millington Driving Center/Farmington Hunt, Elizabeth Lower.

Field Hunter Over 30: Snowy River, Ite Young/Mr. Stewart's Cheshire Foxhounds, Bruce Davidson; Amadeus, Jack Trainor/Mr. Stewart's Cheshire Foxhounds, Jack Trainor; Irish Whiskey, Dr. Stephen Prepstein and Jack Trainor/Mr. Stewart's Cheshire Foxhounds, Joy Carrier.