The father of three had been expecting to wait years for the operation – with an organ donated by a stranger.
But he quickly struck it lucky.
Jack, a 27-year-old gardener, from Thatcham, in Berkshire, said: “People are always telling me we are made for each other, that we’re a really good match.
“Now I owe her my life, without a doubt. She gave me my children, now she’s given me a kidney.”
Full-time mother Kerry Collins, 25, said: “Everyone we knew, who could be a match and was willing, got tested, and it turned out I was the only one.”
The chance of a perfect match between two unrelated people is about one in 100,000.
After the operation earlier this month, the couple are now raising awareness to encourage more people to sign up as living donors and help save the lives of others.
Jack was born with hypoplasia – where the kidney does not fully develop in the womb – and needed his first transplant at the age of seven.
But it started to deteriorate in March.
He needed four hours of dialysis in hospital three times a week, and faced a lengthy wait on the donor register.
Teenage sweetheart Kerry said: “We always knew there was a chance his kidney could fail, and it did.”
Dozens of family members were tested, but were not a match, before Kerry volunteered in July.
Within weeks the transplant took place at Churchill Hospital, in Oxford.
Kerry – who has children Kacie, six, Jayden, four, and Bentley-Jay, one – said: “I didn’t think about losing my kidney, I was more panicky about the fact that I’d never had an operation and I was worried I’d never wake up from the anaesthetic.
“I’d give him a lung if it came to it and he needed it – anything that means we can stay together and with the kids.
“Life has massively improved since the operation.”
Jack added: “I can’t thank her enough. I’d do the same for her if I could.”