Mr Singh acknowledged the rare step he took to help, but said that protocols of his faith did not restrict certain actions in an emergency.
"I wasn't thinking about the turban. I was thinking about the accident and I just thought, 'He needs something on his head because he's bleeding.' That's my job - to help. And I think anyone else would have done the same as me."
Mr Singh and other members of the public stayed with the boy until emergency services arrived. They told him he was going to be okay.
Not long after the accident, the boy's mother arrived.
Mr Singh said: "The little boy, he was talking to us before his mum came. He wasn't crying. But when his mum arrived - when he saw her - he started to cry, because she was crying."
Gagan Dhillon said he was on his way to work when he saw the accident and stopped to help.
"There was enough help as there was, but being a Sikh myself, I know what type of respect the turban has. People just don't take it off - people die over it.
"I saw him [Mr Singh] with no head covering and thought, 'That's strange'. But then I saw one hand was underneath the boy's head supporting it and his siropao [turban] was stopping the bleeding.
" ... he didn't care that his head was uncovered in public. He just wanted to help this little boy."
The 5-year-old was walking to school with his older sister when he was hit. He was thought to have suffered life-threatening head injuries, but last night was in a stable condition in the Starship hospital.
It is understood the boy ran across the road at a pedestrian refuge. There is often a school patrol in the area, but it had finished supervising road crossings for the morning.
Manuroa Rd resident Charmaine Tuhaka said she heard a vehicle skidding, and then a big bang. "I thought it had hit another car. I went running out and saw the little boy. It was quite horrific."
Ms Tuhaka said she and two others held him still to prevent him moving and further injuring himself.
"He was conscious. His eyes were open, he wasn't moving - he wasn't even groaning in pain. His sister was there ... She was crying. Then her mum came. She didn't say a word. She just ran to her son. She was freaking out."