Maisie, a wire-haired dachshund, was named Best In Show at the annual event at Birmingham's National Exhibition Centre on Sunday.
But she became something of a party pooper for owner Kim McCalmont as the pup answered a call of nature on live TV at her moment of triumph.
Luckily, Ms McCalmont had the necessary equipment at the ready, fishing a baggie from her jacket pocket to deal with the mess.
Clare Balding, who hosted the TV coverage of the event on Channel 4, later tweeted: "I admire #Maisie so much to have been able to move well enough to win Best in Show at #Crufts with such a big load inside her little tummy. What a star!"
Maisie, who came up trumps in the hound category, came out on top ahead of seven other finalists, including Pixie the Kerry blue terrier, Frankie the miniature poodle and Zokni, an old English sheepdog.
Ms McCalmont said: "It's a little unbelievable really at the moment, it's something that hasn't sunk in. It's been a very busy day, very hectic.
"She's had a lovely day, she loves the shows."