The visitors took the lead in the 20th minute as Lee Miller scored his eighth of the season from the penalty spot after the former Middlesbrough man went to ground under a challenge from Jamie McCombe. If the penalty was soft, justice was served just four minutes later when Miller handled the ball in his own half and Iain Hume scored from the resulting free kick.
The referee pointed to the spot again in the 30th minute and Paul Parry dispatched to give Preston the lead after a foul by Lubomir Michalik on Hume.
However the match was all square before the interval as Frank Simek’s low cross fell to Francois Zoko in the six yard box and the Ivory Coast striker turned deftly to smash the ball into the roof of Thorsten Stuckmann’s net.
James Berrett fired the Cumbrian’s in front midway through the second half when his long-range effort was deflected, wrong-footing Stuckmann.
Preston could have been forgiven for thinking it was not their day when Nathan Doyle’s 30-yard piledriver hit both posts and somehow failed to cross the line, but in stoppage time Paul Coutts went on a mazy run and drove the ball across the Carlisle goal where 19-year-old substitute Douglas was waiting at the back post to tap in and save the day for North End.