Will Simpson bought a new riding hat to wear during the Washington International Horse Show at Capital Centre this week. He lost it over the fifth of 14 jumps he cleared on his way to his first open jumping victory last night in the $7,500 international jumpers timed first round.

"My old hat had a lot of battle scars on it," said Simpson, 26, of Keswick, Va. "I figured I'd buy a new one so I could at least look the part."

Simpson rode Herban, a chestnut stallion owned by Cabin Branch Farm, in the class in which the fastest horse with the least number of faults is the winner. Simpson was one of only nine riders in an original field of 35 to complete the course of jumps without faults.

In addition to losing his hat, Simpson's horse also hesitated at fence nine but made up for any time lost over the last five jumps, finishing in 48.13.

One of the top riders on the circuit, U.S. Equestrian Team member Katie Monahan, of Middleburg, Va., had to settle for second place after finishing her round aboard Matterhorn in 49.64. "She's an artist," Simpson said. "When she walked into the ring I figured I would be happy for second."

Third place went to West German rider Klaus Reinacher on Desire. Their final time was 51.11.