An enraged cyclist went ballistic on a driver for nearly crashing into him — by pulling out a massive “zombie” knife and using it to try to smash through the car window.

Dashcam footage shows the blue Volkswagen suddenly pulling out of a line of traffic and almost clipping the male cyclist in Croydon in South London, according to the Telegraph.

The cyclist ditches his bike and chases after the Volkswagen, which slams into another car. He pulls out the at least 10-inch hunting knife and attempts to kick in the windows — before bashing the blade into the glass and trying to yank open the doors.

Two panicked people are seen inside the car — and the 19-year-old driver flees when the cyclist smashes through the passenger window.

Two other men are seen in the background of the video running toward the car in an attempt to intervene.

The road-rage incident happened around 5 p.m. Wednesday and no arrests have been made, Scotland Yard said.

“The victim, a 19-year-old man in an attempt to escape collided with another vehicle, exiting on foot. He was followed by the suspect,” a police spokesman said. “The victim later returned to his car after the suspect made off. No reported injuries.”

The attack comes amid a surge in knife crime in London that has left 37 dead this year.

“Zombie” knives can have serrated blades up to 2 feet long, with words like “Zombie Killer” and “Slayer” scrawled along them. They’re popular in the UK, even though it’s illegal to sell or possess them in public, according to the Sun. Officials are working on banning them altogether.