He was walking to a nearby hawker centre for breakfast yesterday morning when a stranger suddenly came up to him.
Staniel Han, 17, said the slim man warned him not to go to the hawker centre at Block 538, Bedok North Street 3, as a fight had taken place there.
The teenager, who works in a local eatery, said: "I asked him if he was all right. He said that he was okay.
"He then took out a bloodstained knife from the waistband of his pants and waved it in my face.
"He said he had cut a guy's hand. He said, 'The hand gone already'. He also told me that he is from a secret society.
"Then he walked away, with the weapon still in his hand. He seemed a bit off, like he was on something."
Staniel told The New Paper that he only half-believed the man, but when he reached the hawker centre, he saw that the floor was covered in blood.
Another resident, who declined to be named, saw the attack when she was going to work at around 5.15am.
The cleaner, 70, said she saw two young men chatting at an open space near the hawker centre when a third youth approached them.
One of them ran away, leaving his friend behind to face the newcomer.
She said: "They got into a scuffle and minutes later, I saw the one who was left behind running towards Block 538. The newcomer ran after him, shouting in Malay, 'Don't run, or I will kill you!'.
"He attacked the guy with a weapon and I saw blood spilling. I quickly left to take a bus and I was trembling in fear."
Responding to queries from The New Paper, the police said they were alerted to the incident at around 5.20am.
They later established that a case of voluntarily causing grievous hurt with a dangerous weapon had taken place there.
Shortly after the attack, one of the victim's friends, who lives on the fourth storey of nearby Block 537, went downstairs to buy some cigarettes and saw the injured man.
The friend took the victim upstairs and allowed him to rest outside his next-door neighbour's flat.
The neighbour, who wanted to be known only as Madam Aini, 61, told TNP that she was jolted awake by the loud sound of somebody pounding on her bedroom window.
When the hawker peered out, the friend asked to speak to her son.
She said in Malay: "He looked very flustered and told me that one of their friends, Ridzwan, had been attacked with a knife."
When Madam Aini and her son went out, what she saw made her blood run cold.
With a shudder, she said: "I saw Wan (Ridzwan's nickname) slumped against a wall, covered in blood. The floor was also bloody and there was a trail from the lift right up to my door.
"The poor kid was barely conscious. He had deep cuts all over his left hand and arm. I was afraid he would die."
Madam Aini called the police while her son tended to the victim and gave him water to drink.
The friend then went home to alert his mother.
The mother, who wanted to be known only as Madam Siti, 64, said: "These boys are all friends with one other. The guy who attacked Wan is also part of their group, but we don't know much about him.
"I don't know how friends could do this to each other. Wan is such a nice kid - very gentle and polite. He likes to ride his skateboard in the neighbourhood."
The Singapore Civil Defence Force sent an ambulance to the scene.
Mr Ridzwan, 25, was conscious when he was taken to Changi General Hospital.
The police said that a 27-year-old man was arrested at around 8pm yesterday in relation to the case.
This article was first published on July 22, 2015.
Get The New Paper for more stories.