In-form Colchester came from a goal down to cruise to their 19th win from their last 21 matches to power back into the top two of League One.
The Essex club did it the hard way as they fell behind in the 37th minute when Dean Windass swept home from close range after Mark Bower had returned a corner into the danger zone.
Colchester hit straight back and were level four minutes later. Greg Halford was the provider with a marvellous cross with the outside of his boot and Richard Garcia was in the right place to head home from the edge of the six-yard box.
Former West Ham man Garcia has now scored in each of Colchester's last four games and he then doubled his tally to put his side in front on 56 minutes.
The Aussie raced on to a lofted through ball by Garry Richards to head cunningly over advancing keeper Donovan Ricketts to notch his sixth goal in the last four fixtures.
Bradford were now on the rack and they duly conceded a third on 63 minutes. Kevin Watson floated over a corner and Chris Iwelumo headed firmly past Ricketts to put the U's 3-1 up and out of sight.
Colchester could have had more goals in the second period and Ricketts denied Garcia what would have been a deserved hat-trick by finger-tipping the Aussie's drive over the top.
Bradford were well beaten although they nearly grabbed a consolation in injury time when a goalbound shot by Windass was well smothered by Aidan Davison against his old club.
This was Colchester's 11th straight home victory and their record nine wins on the spin eclipsed the previous landmark of eight in 1987.