As the ambassador swapped his loafers for a shearer's sackcloth moccasins and straightened his new Golden Shears baseball cap, former world champion shearer Tom Wilson brought him up on stage and sheared most of a sheep, leaving one side for Mr Gilbert to tackle.
Watched by his wife and daughter, and a delighted crowd, Mr Gilbert smoothly completed the shear.
"I started to get the hang of it," he said. "You start to feel how talented these shearers are."
When asked by the Times-Age why he was in Masterton, Mr Gilbert said he had to come specifically to see the Shears.
"This is the world premier show, I had to come here. It's the finest shearing competition in the world."
Mr Gilbert said he knew the basics before he came.
"I have been close to sheep before but I've never shorn one."
The 58-year-old former baseballer fielded the tough question of whether a US president may follow in his moccasin steps across the stage of the world's most famous shearing and woolhandling competition, saying "I will tell him" about the experience, and maybe encourage President Obama to make the pilgrimage one day.
Mr Gilbert grew up in Pittsburgh, Pennsylvania, and showed his own sporting prowess in seven games for professional baseball outfit the Chicago White Sox in 1985.
Mr Gilbert took up his appointment in January - he was not the first US ambassador to cross the Rimutaka Ranges from the embassy in Wellington to visit the Golden Shears. The first was possibly the late John Henning, ambassador in 1967-69.