Kaz Hosaka, a prominent Japanese-born dog handler who guided two miniature poodles to Best in Show victories at the Westminster Kennel Club Dog Show — the second one just last month — died on Sunday in Langhorne, Pa. He was 65.

His wife, Roxanne Wolf, said the cause was a traumatic brain injury as a result of a fall.

Mr. Hosaka was a masterly handler for more than 40 years. Edge, a lifestyle magazine, recently said he was “to the poodle world what Michael Jordan is to basketball. Smooth, clever, elegant and nearly unbeatable.”

In a profile in The New York Times in 2009, he was described as “an artist who tends his poodles’ poufs as if they were bonsai trees from his native Japan.”

Mr. Hosaka radiated intensity, from the backstage grooming area to the green carpeted show rings, said David Frei, a former voice of the televised Westminster show and the club’s former communications director.

“When he’d walk in someone’s ring, other handlers would say, ‘Oh,’” Mr. Frei said in an interview, “and judges would say that must be a pretty good dog if he’s handling it.”

Mr. Hosaka was a poodle specialist who handled all three size varieties: miniatures, toys and standards. He showed the winningest toy poodle in breed history, Ch. Smash JP Win a Victory, also known as Vikki, to 108 Bests in Show and to the ranking of No. 1 dog in the country in 2007. The tiny exemplar of canine topiary also won the toy group at Westminster in 2007 and 2008, although she lost in the Best in Show competition each year.