Making their first appearance ever in the United States, two representatives of the equestrian team from Switzerland -- Gerhard Etter and Thomas Fuchs -- performed faultlessly over a complicated course of 18 obstacles last night to win the International Pair Relay, the first event at the Washington International Horse Show at Capital Centre.

No newcomers to this type of competition, Etter, on his 7-year-old brown gelding Cripello, and Fuchs, on 9-year-old bay mare Tullis Lass, had perfect strategy in negotiating the course.

Speaking through a German interpreter, they explained that their plan was to take every two jumps and then let the other jump the next two. Thay way said Etter, 32, "there is less risk." They previously have competed in five other pair relay events this summer in Europe.

Harvey and Robert Smith, a father and son duo representing Great Britain, came in second in 75.51. Their score was 67.57 with an extra eight seconds added to their time for two knockdowns.

In the original field of 13 pairs, four were eliminated for various reasons.

Before an estimated crowd of 5,000, Buddy Brown, on the aged show veteran star jumper Idle Dice, and Terry Leibel, riding Volunteer, also put in clean rounds in a time of 77,000 to place third in the class.

Fourth place went to the second entry from Switzerland and the first pair to enter the competition, Walter Gabathular on Why Not III and Kurt Maeder on Abrazon.

The first and fourth-place finishes for Switzerland, considered by most to be ranked fourth out of the four international teams in competition here, gave them the lead in the team standings.

Earlier in the evening, one of the horses in the carriage competition collapsed in the arena and had to be taken from the hitch and led out by a groom. The class was held up for approximately 30 minutes. Clay Camp of Keswick, Va., a well-known figure in thoroughbred racing, was declared the winner.

Today's show will feature the firstl- and second-year green working hunters and two classes of international jumping.