Dramatic video caught the moment police finally cornered a sword-wielding maniac in London early Tuesday, ending a rampage that killed a 14-year-old boy and injured four other people, including two hero cops.

Doorbell footage shows a squad car with its siren blaring screeching to a halt outside a house where the suspect clambers over a fence into a yard at least 22 minutes after he first crashed his van into a London house and started stabbing people, according to police.

The attacker quickly holds aloft a Samurai-style sword while pulling the hood of his yellow sweatshirt over his head, turning to confront approaching officers.

As he paces in the yard, still brandishing the terrifying weapon, the swordsman is confronted by several officers screaming orders — finally falling to the ground after being shocked at least three times with Tasers, the footage shows.

Seven officers then contain him on the ground, with one yelling: “Don’t move — don’t f—ing move!”

Within seconds, a flurry of other officers arrive, with one yelling to “f—ing cuff him!”

The suspect, only described as a 36-year-old man, was finally arrested 22 minutes after the first emergency call about the 7 a.m. rampage in Hainault — even though he was himself seriously injured when crashing his van at the start of his rampage, police said.

During the chase, the suspect was also seen walking on garage rooftops — then jumping into gardens to evade chasing officers, other footage shows.

“He’s going in people’s gardens, man,” one panicked-sounding man yelled as cops were directed toward the runaway swordsman.

“Lock your doors! Everyone lock your doors!” the same man watching the suspect shouted desperately.

The suspect was arrested on suspicion of murder after a 14-year-old boy died from being stabbed in the attack, which is not thought to have been targeted, police said. Neither the dead boy nor the suspect were immediately identified.

The four other victims — including “brave officers stabbed during the incident” — remained hospitalized with injuries not thought to be life-threatening, Assistant Commissioner Louisa Rolfe said.

The suspect remained hospitalized late Tuesday and “given his injuries, we have been unable to interview him,” Rolfe said in a late afternoon update.

Police said they do not believe the attack was terror-related or targeted — and the suspect did not appear to have a record.

“Despite urgent checks of our system today we have found no trace of a prior incident involving him,” Rolfe said of the” fast-moving, complex incident and investigation.”

“As a matter of urgency, we are trying to understand exactly what happened and why,” the deputy commissioner said.

Chief Supt. Stuart Bell described the incident as “truly horrific.”

“I cannot even begin to imagine how those affected must be feeling,” he said outside the homes in east London where the attack happened.

Prime Minister Rishi Sunak called it “shocking,” and King Charles II sent his thoughts and prayers to the slain teen’s family and saluted the courage of emergency workers, Buckingham Palace said.

With Post wires