Michael Jackson was there with Brooke Shields. Peter Pan and Tinkerbell were there, too. So were Dorothy and Toto along with Dolly Parton and Bette Midler.

The occasion was the riding partners phase of the $7,500 Gallo Wines international-open jumpers class last night at the Washington International Horse Show at Capital Centre.

In the rotating pair relay class, two riders team up to jump the entire nine-obstacle course twice in correct order. One riding change is mandatory and there is no maximum number of changes. And last night, the riders were celebrating Halloween in costume.

But as surely as the costumes added color, they added problems for the riders. Olympic gold medalist Joe Fargis, aboard Herban, and Katherine Burdsall, aboard Monroe, dressed as characters from "Cats," got caught up in the festivities and appeared to forget which obstacle to jump. Still, they were fifth among 16 pairs with a 53.41 seconds.

Great Britain's entry, Robert Smith aboard Sanyo Alabama and dressed as Prince Charles, and Tim Grubb aboard Cat's Whiskers and appearing as Lady Diana, won in 49.32. Brothers Peter and Mark Leone of Franklin Lakes, N.J., (Tarzan and his gorilla) were second in 52.68 seconds.

Katie Monahan (Dolly Parton) aboard Everon and Terry Rudd (Bette Midler) on Kalypso were third in 52.79 seconds. Donald Cheska as Michael Jackson and top-ranked U.S. Grand Prix rider Michael Matz as Brooke Shields, finished fourth aboard Eadenvale and Alwin's Ace, respectively, in 53.07 seconds.

The U.S. equestrian team continues to lead team standings with 55 points, Great Britain trails with 39. Canada did not add to its 25, but won the team costume competition. The Canadians appeared as the Jackson family "Victory Tour," complete with a white-gloved Michael and a moonwalking gelding.

Honest Tom, a chestnut gelding ridden by Ellen Van Dyke for her parents, captured the $3,000 Insilco Jumper Classic in the afternoon.

Honest Tom cleared all fences without problem in a brisk 24.712 seconds. Cheers, with D.D. Alexander riding, was second with a clean 25.185 clocking, followed by Pachelbel, riden by Dini Santangelo of Harrison, N.Y.

Cheers and Alexander, 21, won up the Insilco series championship with a record-breaking 110 points, the first time in the series' seven-year history a rider has broken 100 points.

Pure Olena, ridden by Allen Mitchels of Michigan City, Ind., won the open championship cutting competition.