The 29-year-old, coming in at his lightest ever weight, also picked up the vacant vacant WBA International belt, further increasing his prospects of another shot at a world title.
However, it was a slow start from the Finchley fighter, who took a big left hook from the Czech in round one, before walking onto another at the start of the second.
Chisora managed to muscle his way into the contest, forcing his opponent onto the back foot by the time the bell sounded to end round two.
The referee had to step in to intervene with 35 seconds left in the third, when 'Del Boy' caught Pala with a series of devastating blows that forced him to slump in the corner with his back to the action.
Victory takes Chisora's professional record to 19-4.