Mum-of-two Suzanne Davies, 38, suffered renal failure and was told she'd have to spend the rest of her life on dialysis unless a new kidney could be found.
Step forward Suzanne's partner of 10 years Neil Parry, who didn't hesitate to offer the amazing sacrifice when it was discovered he was a near-perfect match.
Both parents went under the knife at the University Hospital of Wales, Cardiff, in December and Neil's kidney was transplanted into Suzanne.
And although Suzanne is still in hospital with a minor infection, she is well on the road to recovery.
Suzanne said: "He is my hero and my saviour. I'm so lucky to have him in my life.
"For the last 10 years we have been together he has seen me suffer with my health. He could have walked away but he didn't.
"He has stuck with me through thick and thin and now he has given me a new lease of life. I can't thank him enough."
Suzanne, from Merthyr Tydfil, has suffered with a rare disorder of the adrenal glands, called Addison's Disease, since she was just eight years old.
She has needed regular medication for nearly three decades to replace two essential hormones she lacks in her body called cortisol and aldosterone.
But her health took a dramatic turn for the worse two years ago when her kidney function began to deteriorate.
She said: "I was being sick quite a lot and for the past 18 months I've been suffering with gout and getting lots of infections.
"When I went to see a consultant in September and he said I either needed a transplant or dialysis."Both my mum and Neil were a match but it was best to go with Neil as he's younger and more healthy. It was a big step for him."
The pair met 10 years ago on a night out in Swansea and have remain inseparable since.
They have two children together, nine-year-old Cole and five-year-old Isla, and also lost a daughter at just a day old in 2008.
Suzanne added: "Neil is my best friend and we've been through so much together.
"He has changed my life for the better so our two beautiful children can have a healthy mum.
"We might get married at some stage, but I don't need a piece of paper to prove how much we belong together.
"I'd rather hand over all the wedding money to charity."
Neil said: "If she'd gone on dialysis she'd need three visits a week to the hospital - and people on dialysis get very poorly.
"Having the operation meant we were both out of action for a just couple of months, rather than anything long-term.
"We are a strong couple."
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