SINGAPORE - She was speechless with joy when she found out she had been named the first Straits Times Singaporean of the Year, but it turned out to be a bittersweet win for Madam Noriza A. Mansor.

The sales assistant, 50, won the inaugural award for her good deed in helping an elderly stranger, Mr Tan Soy Yong, when he soiled himself in public.

But the thought that Mr Tan could not be there with her brought tears to her eyes.

She said: "I am very happy but also a bit sad because uncle (Mr Tan) could not be here today. But when I went onstage to take the award, I could feel like he was here with me, somehow."

Madam Noriza met Mr Tan in October 2014 in a Toa Payoh supermarket, where he had soiled himself while buying groceries with his wheelchair-bound wife, Madam Lee Bee Yian. Both are 76.

Others in the Toa Payoh supermarket recoiled from the old man and the stench. But Madam Noriza not only bought him a new pair of shorts but also knelt to wipe faeces off his legs.

Since then, she has spent nearly all of her days off visiting the old couple - initially at their three-room flat in Potong Pasir, and later in the various hospitals and nursing homes they were moved to.

The couple are now warded at a Serangoon nursing home.

Madam Noriza rushed to visit them once the ceremony was over, stopping only to buy fried rice and coffee for them at a nearby hawker centre.

But she was told that Mr Tan came down with a high fever after her last visit two weeks ago, and he is now at Tan Tock Seng Hospital.

When she visited him there, she found him lying in bed with a tube up his nose. He did not respond to her attempts to speak to him, but stared blearily into space.

"He has lost so much weight," said a distressed Madam Noriza. "Seeing him like this makes me want to cry."

Having lost her own parents when she was 21, she now treats the elderly couple as her "own father and mother".

"I think God sent them into my life," she told The Straits Times when she visited Mr Tan last year.

Prime Minister Lee Hsien Loong, who presented her with the award, later congratulated her in a Facebook post. "Glad her selfless act was acknowledged," he wrote.

ST editor Warren Fernandez, one of the award's 15 judges, said he had been moved by her readiness to cross barriers of age, language and race to help a complete stranger. "How many of us would have done the same?" he wondered.

"All the nominees were worthy finalists, but there was something quite special and inspiring about this lady. I think all of us have something to learn from her."

Madam Noriza, a bedsheet promoter, often works 12-hour days and usually gets one day off a week.

Asked what she will do with the $20,000 cash prize, she said she would use some to renovate her four-room HDB flat in Tampines, especially the kitchen, which she has not upgraded in 20 years.

She plans to save the rest for her five children aged 12 to 27, whom she single-handedly raised.

Three of her children, along with her son's fiancee, attended Tuesday's ceremony with her. Her eldest son, airport relations officer Muhammad Nazri Zul, 27, said: "My mother really sacrificed a lot for our family. She was the only one with us throughout all the hardship.

"There is no 'me-time' for her. That's why when she is free, she will visit uncle and auntie. She doesn't understand having her own time to spend on herself.

"You know what they say, that good things happen to good people? I guess winning this is her reward for all the good things she's done in her life."