Nottingham Forest midfielder Andy Reid piled on the misery for Bradford boss Nicky Law as his injury-time strike stole all three points from under the Bantams' noses.
Bradford old boy Eoin Jess had clawed the visitors back into the contest with his first of the season, but it was cruel luck on City when Reid fired home the winner.
The home side deserved at least a point from a much-improved display, but their hard work was undone when Reid was allowed to run through the middle and let fly with a right-foot drive from 25 yards.
After just two points from their last seven games, struggling City got the morale-booster they were looking for in the fifth minute when striker Michael Branch superbly finished off a swift counter attack.
Forest full back Wes Morgan lost possession on halfway, and when John Thompson's attempted clearance rebounded kindly for Andy Gray, he curled over a teasing cross from the right.
Branch, who had been sidelined for the last four matches, still had plenty to do, but he twisted in mid-air to send a looping right-foot volley over keeper Darren Ward from eight yards.
City skipper Dean Windass wasted a great chance in the 10th minute when he pulled his shot wide after more good work by Branch, but Bradford keeper Alan Combe was rarely troubled as Forest were restricted to long-range efforts.
The Bantams had a strong penalty appeal for waved away early in the second half, but luck seemed to be on their side when Reid deflected a Mathieu Louis-Jean shot against a post and the ball bounced away to safety.
Bradford ended a run of seven defeats in the game against Forest last season, but there was no repeat this time thanks to two late lapses in concentration.
Jess took advantage of Reid's flick-on to fire Paul Hart's side level with a right-foot drive from just inside the Bradford box in the 77th minute, and with City's defence standing off Reid snatched the late, late winner in dramatic fashion.