Katie Monahan, riding for the first time this season as a member of the United States Equestrian Team, won the $7,500 International Open Jumper class at last night's opening of the Washington International Horse Show at Capital Centre.

The 28-year-old Monahan, of Upperville, Va., and Grey Chief, an aged gray gelding, toured the course of 10 jumps without error in a time of 39.88 seconds.

Second place in the class of 30 international riders went to Michael Matz on Honest Tom, who also finished without faults, but in 40.03.

Monahan, who has been riding on the grand prix jumping circuit for 10 years, said this has been her most successful year with three major victories.

"Having a lot of horses is what made my year so good," Monahan said. "I am able to alternate horses each week so that none of them get burned out."

Grey Chief has been to only 12 shows this season. "I rode him in Florida in February and then didn't show him again until July," she said. "He's so smart he knows how to turn. He knows all the tricks. He's one of the best turners I've ever ridden.

"If I just lean to one side he wheels in that direction," she added. "He's almost like a cutting horse."

Monahan said the sharp turns she made on Grey Chief and his long strides are what helped her win. "I was also able to watch some of the others go first," she said. Monahan was the 24th rider to perform.

Earlier in the timed first round, veteran Rodney Jenkins of Gordonsville, Va., was sixth to perform and took the lead for a short time on Arbitrage, clocked in 42.25.

But seven riders later Matz, 29, of Collegeville, Pa., came in to better Jenkins' time, only to be later left behind Monahan.

Monahan's victory put the U.S. team in the lead with 10 points. Switzerland was in second place with four points, after Thomas Fuschs placed third on Willora Carpets.