The unbelievable sight was filmed on the 15 Freeway in Los Angeles County and posted to Facebook by another motorist, Brian Steimke.
In the video, the big rig is caught dragging a Nissan Maxima, and the truck driver apparently doesn't even realize it.
The tires were blown out of the Maxima and the helpless driver is seen waving his hands, begging for help as Steimke got closer.
Steimke told Inside Edition: "He was trying to wave people down and everyone was trying to get the semi to stop."
It went on for a half excruciating mile until finally, the truck driver came to a stop.
Steimke got out of his car and approached the driver, telling him, "The guy's underneath your car!"
The driver said he "didn't know" he had a car stuck under his truck.