His victim lay motionless, but that did not stop one 45-year-old man from kicking, punching and stomping on him in full view of shocked bystanders.
The man, who was not identified, was arrested for voluntarily causing grievous hurt and suspected drug-related offences after his violent rampage at Block 182A Rivervale Crescent on Tuesday (Sept 22) afternoon, police said.
The 47-year-old on the receiving end of the man's blows was conscious when conveyed to Sengkang General Hospital, they added.
The perpetrator had apparently recommended the victim for a cleaning job. However, their relationship soured due to the latter's lacklustre work and led to the altercation, Shin Min Daily News reported.
The two men argued before exchanging blows, an eyewitness told the Chinese daily.
In the course of the fight, the victim fell to the ground, but the other man did not let up on him, he said.
Video footage of the incident, which was shared on Facebook, showed the younger man, in black, shouting Hokkien vulgarities as he rained blows on the older man who was sprawled on the ground.
He punched, kicked and stepped on the victim's head repeatedly before pointing his finger in his face, yelling inaudibly, and stalking off.
He then left the scene but was reportedly later arrested at his Ang Mo Kio home.
"My leg hurts and I use a walking stick. I also have heart problems, so I didn't dare to go over to offer help," the eyewitness explained, adding that another passerby rendered assistance by supporting the injured man and moving him to the side.
The victim was reportedly bleeding from his left ear, nose and mouth. He also appeared to have suffered fractures to his face and abrasions on his head and cheek.