A career criminal stabbed a straphanger on a Manhattan train — and then knifed another man who tried to stop him from running away from cops in a caught-on-camera pursuit, police sources said Wednesday.

The subway victim, 55, was aboard a southbound A train near Canal Street around 7:20 p.m. Tuesday when he asked 40-year-old Ronald Cundiff to move his bag from a seat, sources said.

Cundiff allegedly refused and instead “took out his knife and stabbed the victim” in the torso, a source said.

The suspect then ran out of the Canal Street station and fled to the Bowery — where he allegedly stabbed the second victim, a 21-year-old man, while being pursued by officers, sources said.

Cellphone video obtained by The Post shows responding cops going after Cundiff as he bolts across the street. Two cops fall into a car as the suspect makes his way to the other side. Seconds later, the clip shows, cops nab Cundiff.

Cundiff, a Bronx resident who has 25 prior arrests, was slapped with charges of assault, criminal possession of a weapon, reckless endangerment and resisting arrest.

The stabbing victims were taken to an area hospital in stable condition.