Pilot Adrian Choo was driving home along Ang Mo Kio Avenue 6 on Wednesday afternoon when he noticed an elderly man waving at him.
"I thought he was most probably a jaywalker," said Mr Choo, 44, who slowed his car to a stop for the man.
But instead of crossing the road, the man ran towards Mr Choo's car and jumped on his bonnet.
Fearing it might be a ruse to cheat unsuspecting drivers out of money, Mr Choo submitted video footage of the bizarre incident, captured on his dashboard camera, to citizen journalism website Stomp.
In the 20-second video, the old man, dressed in a loose white T-shirt and shorts, is seen hurling himself at the stationary vehicle. He is then seen removing his spectacles, rolling off the car, and walking away.
Mr Choo said he did not get out to confront the man partly because he did not wish to hold up traffic. "I also wasn't sure if he was mentally unstable," said Mr Choo, who was in the car with his 11-year-old daughter.
He added that he believes the man left because he spotted the dashboard camera.
"It was quite shocking. What if I didn't have a camera? It would just be my word against his," said Mr Choo, adding that he made a police report on the matter yesterday.
"I hope other drivers will be aware of him. Judging from his demeanour, it seems like he's practised."
Yesterday, residents in the vicinity identified the man as an 80-year-old resident of Ang Mo Kio.
"He cycles around the area. He's quite strong," Mr Jack Tan, 54, told The Straits Times.
Mr Lim Kay Chuan, 52, who is unemployed, said: "He usually sits at the void deck of Block 203, Ang Mo Kio Avenue 3. Sometimes he plays mahjong there."
When contacted, a police spokesman confirmed that a report had been lodged, and said they were looking into the matter.