Tory Lanez Seen Being Stabbed Repeatedly in Brutal Prison Fight, on Video

Tory Lanez's harrowing stabbing was caught on camera in prison ... and it's clear from the video that he's lucky to be alive.

We've obtained video from prison security cameras showing a man who appears to be Tory getting knocked to the ground by another man -- allegedly Santino Casio. This other man jumps on top of him and brings his arm down on him multiple times.

Tory -- lying on his back -- flails about, kicking his legs up at his attacker to fend him off before he sprints down a flight of stairs away from him.

Screengrabs are also making their way around social media capturing Tory covered in blood, easily identifiable from the gun tattoo on his stomach.

We broke the story ... Tory was stabbed 14 times behind bars at the California Correctional Institution in Tehachapi earlier this month -- seven times in the back, four times in the torso and three times in the head.

Lanez was rushed to a local hospital for treatment, but he was returned to prison once he recovered from the stabbing. He was reportedly moved to a new prison a few days later.

We spoke with Casio ... and he told us he heard through the prison grapevine that Lanez planned to attack him. When Lanez was walking his way one day, Santino swore he saw an object in Lanez's pocket that appeared to be a weapon of some kind -- so, he struck first.

Tory has received support from notable public figures like Drake and Florida Congresswoman Anna Paulina Luna over the shooting that landed him in prison. They've both called on Governor Gavin Newsom to pardon him.