Winning Crufts is something that "always happens to someone else", the breeder of the Best in Show said.
Jim Irvine, breeder of Flatcoated Retriever Jet, said taking the coveted title was the "ultimate prize".
The pair beat off opposition from 21,000 dogs, including six other which reached the final at Birmingham's NEC as Crufts celebrated its 120th anniversary.
Nine-and-a-half year old Jet, won the Best Gundog category then went on to be pronounced Best in Show after four days of competition.
Speaking after last night's win, Mr Irvine said: "It's a fantastic feeling, I'm absolutely delighted to have won Best in Show.
"It's just an unbelievable win, I'm just so happy.
"In the dog world this is the ultimate prize, this is what everyone aspires to and normally I find it's always someone else who wins this."
He said the win was particularly emotional as he had previously co-owned Jet with the father of his current owner Iain Ross, who passed away in 2003.
"He still stays with Mr Ross's son so he is still a family pet for the Ross household," he said.
"He stays with me a fair bit anyway but he is a dog that I have seen every fortnight since he left home at eight weeks.
"To have a good dog and to get this far is just unbelievable."
Mr Irvine said he did not know the secret to winning Crufts, but said Jet had never let him down.
"You've got to have a good dog obviously and keep him in good condition.
"But he enjoys it, he is a happy dog and he never let's me down, no matter which show it is."
Jet's owner Iain Ross added: "I am over the moon, I can't believe it. It's a lifetime achievement, it's wonderful."
The Kennel Club said around 138,000 people came to watch the 21,422 dogs compete over the four-day show.
Caroline Kisko, Kennel Club Communications Director, said: "We give our congratulations to Jet who has taken the prestigious Best in Show Award, his breeder and handler Jim Irvine and proud owner Iain Ross.
"Jim and Jet were a pleasure to watch and clearly have a great relationship."
Reserve Best in Show went to Jilly, a two-year-old Petit Basset Griffon Vendeen from Wallingford, Oxfordshire, winner of the Best Hound category.
Also in the final were: German Shepherd Elmo, who won the pastoral group; Boxer Max, who won the Working Group; Wire Fox Terrier Henry, who won the Best Terrier category; Theo, a Standard Poodle, who took first place in the Utility group; and Eric, a Bishon Frise which won the Toy category.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies