Not since 1960 have the Bantams lost at Turf Moor but that impressive record was left in tatters as Burnley turned in their best performance of the season.
Star man was former Bradford City striker Robbie Blake but spare a thought for ex-Burnley keeper Marlon Beresford who conceded four and yet was rated the visitors star man.
Chadwick's goals were the icing on the cake for Stan Ternent's side but Burnley finally put themselves in the driving seat after a tight opening half with the opening goal just before the break.
Ian Moore scored the crucial goal, opening the Clarets' account in the 42nd minute after good approach play by Blake.
Ironically, the visitors had had the better of things up to then and when Delroy Facey contrived to shoot wide of an open goal from six yards many Burnley fans feared a Bradford City backlash.
Chadwick though had other ideas and after firing home following good work by Gareth Farrelly, the former Manchester United winger scored from the edge of the box after Bradford had failed to clear a left-wing cross from Mo Camara.
The final word was left to Blake who showed magnificent technique to slip a shot beyond Beresford after Farrelly, on loan from Bolton, had once again loaded the gun.
Burnley: Jensen, West, May, Todd, Camara, Farrelly, Grant, Chadwick, Blake, Alan Moore, Facey. Subs: Roche, Weller, Branch, Chaplow, O'Neill.
Bradford: Beresford, Francis, Wetherall, Gavin, Heckingbottom, Summerbee, Evans, Gray, Emanuel, Windass, Branch. Subs: Cornwall, Muirhead, Edds, Sanasy, McHugh.
Referee: M Dean (Wirral).