Ma Van Tang, 33, was detained Wednesday as police in Phu Luong District of Thai Nguyen Province probe him for "robbery."
He told police that around Tuesday noon, he booked a taxi and when it reached an isolated area, he pulled out a knife and held it against the driver's throat, demanding money.
The driver pushed away the knife, kicked the door, got out, and escaped, suffering only minor injuries to his face and neck.
Tai then moved to the driver's seat and attempted to take the car. But since he did not know how to drive, later got caught by police.