BROOKLYN - The would-be victim in a botched robbery disarmed the suspect with his car in Canarsie Friday.

The two met up between East 84th and 85th streets on Avenue M to complete the sale of a pair of high-end sneakers in which a teen was the buyer, according to authorities.

The 17-year-old allegedly pulled a gun on the 39-year-old seller inside the latter's gray Honda Pilot. The suspect allegedly demanded the sneakers and cash, officials say.

A neighbor's security camera recorded part of the incident. The video shows the suspect enter, then exit the Honda and cross the street. The driver turns the vehicle around and runs down the suspect.

Police say the impact tore through the teen's right arm, nearly severing it completely. Witnesses say the collision sent the weapon flying onto a neighbor's lawn. 

The teen tried to flee on a nearby MTA bus, but the victim gave chase.

The suspect collapsed on East 86th Street, where police arrested him.

Officials say the teen was taken to Brookdale Hospital where doctors would try to reattach his arm. The result of that effort was not immediately available.

Police charged the driver with attempted murder and the teen with robbery and criminal possession of a firearm.