Katherine Burdsall hung on tightly as she guided Dutch-bred Melton Mowbray over a reduced six-obstacle course during a second jump off, winning the $5,000 General Dwight D. Eisenhower Memorial Perpetual Trophy in the International-Open Jumper Class last night at the Washington International Horse Show.

The 9-year-old brown gelding was the last of five entries to return for the jump off after an original field of 29 horses toured an 11-obstacle course. By going last, Burdsall knew she had her work cut out for her because Boing, ridden by U.S. equestrian team member Leslie Burr, sharply cut corners with grace and ease for a perfect 24.66 seconds.

"A fast, clean round was winning, so I had to take the best shot I could -- go the fastest -- in order to win," said Burdsall. At the final of two closely placed fences, she cut tightly and began the jump close to the fence. "The distance was very tight. It was the only place you couldn't take a chance and risk jumping at a great speed. You couldn't take too big a chance."

Melton Mowbray was clocked at a sizzling 23:53 without fault, giving Burdsall the lead in the national rider standings with nine points and the leading lady rider title with nine points. Burdsall, riding in her first year on the American Grand Prix Association Circuit, won her first Grand Prix two weeks ago in the $50,000 Baltimore event.

Boing was second, followed by Corsair, with Terry Rudd of Westport, Conn., aboard, in 31:49. I Love You, with New Yorker Norman Dello Joio, was fourth with four faults in 24:24. Touch of Class, with Olympic gold medalist Joe Fargis of Petersburg, Va., knocked down three rails for 12 faults and 31:52 seconds.

The first round of the Eisenhower event, scheduled to run earlier in the afternoon, was canceled after the entire class refused to warm up in the backstage schooling area, citing slippery and unsafe turf. Tons of dirt, a combination of loam and clay mixed with sawdust, were removed by an excavation company and replaced with drier dirt.

In early afternoon competition, Charlie Weaver of Keswick, Va., showed Just For Fun, a 7-year-old bay gelding, for Mrs. Sidney Kerr and Cistmont Manor Farm, winning the blue ribbon in the regular conformation hunter class. Sunny Side Up, a 9-year-old chestnut owned by James R. Trueman Amlin of Ohio and ridden by Patty Johnson, was second, followed by Nativation, ridden by Katie Monahan. Monahan, 30, from Upperville, Va., is the third-seeded rider on the Grand Prix circuit, but was barred from regular international-open jumping competition after missing the entry deadline here.