by Alastair Leithead [BBC correspondent in Cape Town]
Employed at first as a gardener, Mr Naki worked his way up to become even more nimble-fingered on the operating table than Professor Barnard himself.
-- Hamilton Naki
His work helped the first heart transplant become a reality and for years after that he passed on those skills to thousands of young surgeons.
Until recently his story was ignored, but now a film-maker hopes to change all that.
Professor Barnard carried out the first heart transplant in the Groote Schuur Hospital in Cape Town where years earlier Mr Naki enrolled as a gardener.
Now a great-grandfather of 78 he lives in Langa township a few miles from the hospital - living on his gardener's pension.
But the research he did with animals paved the way to the pioneering operation.
"I was taken on to work in the garden. After a while I changed to work in the medical school in the clinical labs where they were working with dogs - eventually to work on open heart surgery and pulmonary bypass and so on."
"Here in South Africa nobody wanted to work with the animals as it was so dirty."
Film producer Dirk de Villiers is now working on a documentary of Mr Naki's life.
Professor Barnard died two years ago, but among the footage is an interview with the surgeon speaking about Mr Naki.
"I could see that he was a very capable young man and I gave him more and more to do and eventually he could do a heart transplant sometimes better than the junior doctors who came there."
Mr de Villiers, an old friend of Professor Barnard, is also making a biographical feature film called simply "Barnard".
<-Bernard said Naki was better at stiching than he was
He is giving Mr Naki a more important role than he had in reality - to redress the balance.
"I want justification to be done to Hamilton Naki because I think he's a remarkable man."
"I think that he's a role model for any young black man not even in South Africa but in the world. That is that you don't need to have the education or a certificate against a wall if you develop a skill."
He added that under apartheid there was very little recognition for a black man and he wanted Hamilton Naki to be recognised by the world "as one of the great researchers of all time in the field of heart transplants".
Mr Naki was given special permission to work, researching pioneering techniques with the animals in the laboratory.
Professor Barnard even said he was a better craftsman when it came to stitching than he was. Mr Naki said Professor Barnard had arthritis so he would often help him teach.
Accepting the system
When asked if he was disappointed he did not become a surgeon himself he replied: "Those days you had to accept what they said as there was no other way you could go because it was the law of the land."
The Groote Schuur Hospital still has photos of Mr Naki in the transplant museum. But his memory lives longer in the minds of those surgeons taught by him.
"Hamilton was very skilled not only in the surgical aspects, but in the anaesthetics aspects of animal research. If he hadn't been black he would have been given the opportunities to undergo medical training," said Professor Del Kahn, the hospital's head of surgery.
But he has been given a presidential award for his achievements - the Order of the Mapungubwe - one of the highest honours in South Africa.
"I can be happy now that everything is out. The light is lit and the darkness has gone," he said.