As a regular blood donor for almost a decade, Mr Sakthibalan Balathandautham, 28, was no stranger to helping patients in need.
While checking his Instagram messages in July last year, he came across a plea by a young couple looking for a liver donor for their one-year-old daughter, Rheya.
This, he thought, was a calling, a chance to give a new lease of life to a baby he had never met.
"When I saw it, I thought to myself, there's a girl out there, who is very young, who is looking for a living liver donor. I felt this was an opportunity for me to step up and do something bigger," he said.
He spent three hours reading up on transplant procedures and felt heartened that donors could recover quickly and usually resumed their normal lifestyle after surgery.
At about 1am that night, the sales executive contacted the couple and offered to be a donor.
After several rounds of tests, he donated 23 per cent of his liver to Rheya on Sept 30 last year.
For his selfless act, Mr Sakthibalan was nominated for The Straits Times Singaporean of the Year award this year.
A few weeks after her birth in July 2019, Rheya was diagnosed with biliary atresia - a rare disease in infants where the bile ducts in the liver are inflamed, blocking bile flow to the gall bladder. It eventually leads to liver failure.
Despite surgery to improve her bile flow, Rheya's condition did not improve, and her parents, Mr Sunil Jayakumar, 31, and Ms Ruthra Saravanan, 30, were told she would need a liver transplant.
As many of their family members and friends did not share Rheya's blood group, and some were stuck overseas due to the pandemic, the couple posted a plea for a suitable liver donor on social media.
In the weeks before the operation, Mr Sakthibalan underwent a series of tests, including the donor suitability test, as well as an interview with an ethics committee where he was told about the risks involved and asked why he had offered to be a donor.
He was discharged four days after the operation and soon resumed his normal lifestyle. Rheya began a slow and steady recovery process, which included taking immunosuppressants to prevent transplant rejection.
What started as a phone call has blossomed into a beautiful bond between Mr Sakthibalan and Rheya's family. Now, a visit to Rheya's home is a chance for him to catch up with her parents about work and family.
Rheya, now two, calls him "mama" (uncle in Tamil) and is eager to show him her toys and sing nursery rhymes together.
Seeing her recovery journey has been fulfilling for Mr Sakthibalan.
He said: "Before this experience, I never knew what it meant to be a living organ donor.
"Seeing Rheya now, I know my decision was the right one."