All seemed fine at the break as former Darlington striker Barry Conlon was adjudged to have handled inside the area in the tenth minute. Referee Darren Drysdale pointed to the spot and midfielder Clark Keltie smashed the ball past Scott Loach in the Bradford goal.
Bradford had been poor with only a shot from Tom Penford in the 12th minute and a close-range effort from captain David Wetherall four minutes from the break their total contribution to a disappointing opening 45 minutes for the visitors.
But manager Stuart McCall's half-time pep talk worked wonders as Conlon began to run the show.
In the 50th minute Conlon laid the ball off to Peter Thorne, whose low cross was met by Penford who fired low into the bottom corner of the net for the equaliser.
Darlington keeper David Stockdale saved with his legs five minutes later as Conlon inspired another good move finished off by Thorne.
Another former Quakers favourite put another nail into the Darlo coffin in the 63rd minute when defender Paul Heckingbottom sent a free-kick deep into the area onto the head of Conlon, who looped the ball over Stockdale from 12 yards out.
A string of bookings and substitutions followed before Penford almost turned the ball into his own net from a Rob Purdie cross. The ball struck the crossbar however and three minutes later the win was secured for the visitors.
Again it was another former home favourite who did the damage. Joe Colbeck was a loan player at Darlington and he picked up possession on the edge of the area before racing into the box and firing low beyond Stockdale's desperate dive.
The home side were down to ten men in the 83rd minute when Foran was sent off for a foul on Colbeck and the straight red card means he will miss Darlo's next three important fixtures.