John Kear’s side had left their fans nervous when leading just 12-8 heading into the final quarter at Odsal.
They had scored three tries but failed to convert any, meaning it allowed a spirited Workington side to get close when Elliott Miller latched onto Carl Forber’s grubber in the 52nd minute.
However, Hitchcox - the Australian winger who started the season with Super League Castleford Tigers - scored his second in the 63rd minute to ease tension and, after Workington’s ex-Kiwi prop Fuifui Moimoi was red-carded for an awful high tackle, he gleefully raced in for his third.
It was a hard-earned success for Kear’s side who, at the back of their minds, always knew these opponents were the only team they had failed to beat during the League 1 season.
Bulls lost on both occasions and when they fell 24-18 to the Cumbrians at Odsal in August, it essentially ended their hopes of claiming the title and sole automatic promotion place.
Rivals York City Knights took charge instead and it was those defeats that left the former World Club champions in this difficult situation.
However, led brilliantly up front by forwards Ross Peltier, Steve Crossley and Elliot Minchella, they managed to recover their poise to get home.
Workington winger Joe Hambley spilled Dane Chisholm’s crossfield kick to gift Bulls field position and they shifted it right for Hitchcox to get over with a fine finish in the corner.
Crucially, Chisholm managed the conversion, too, and then slotted a drop-goal four minutes later.
Moments later, Moimoi had his moment of madness with an wretched high tackle on Bulls prop Liam Kirk and, even though Chisholm missed a simple penalty, Hitchcox made sure.
There was even time for ex-Hull KR stand-off Chisholm to race in for one at the death as the celebrations began, prop and captain Crossley narrowly missing with the touchline conversion attempt after the hooter.
Workington battled hard, especially given they lost experienced prop Oliver Wilkes (calf) and hooker Sean Penkywicz (hamstring) to first half injuries.
Bradford only led 12-2 at half-time but should have been further ahead after they failed to convert any of those tries.
Joe Keyes missed the two kicks and when Chisholm took over duties, he, too, was left with the same unedifying result.
Still, Bradford were thankful of the advantage given they were just 4-2 ahead until back-to-back tries just before the break made the difference.
First, George Flanagan, the effervescent hooker who always has an impact off the bench, threw an outrageous dummy on the last tackle to go over from acting half in the 36th minute.
Then, in the next set, stand-off Keyes scored a lovely solo try, crabbing across the Workington line, teasing his opponents with dummies before arcing and easing through from 40m.
His side had started well, too, with Hitchcox rounding off a smart shift to the left inside four minutes.
In between those periods of scoring, however, Bradford did not have it all their own way.
Needless penalties - Chisholm was pinged for dissent and Matty Garside yellow-carded for preventing a quick 20m tap - encouraged the visitors who, with veteran half-back Carl Forber probing, always posed a threat.
Nevertheless, Bradford’s actual line did not look truly troubled when down to 12 men, Forber making do with a penalty when they were back up to 13.
But it would be Bulls’ day as they made their way back into the Championship, Workington having one last chance when they face Swinton Lions - bottom of the Championship Shield - in next week’s final play-off game.
Bradford Bulls: McNally; Hitchcox, Gibson, Oakes, Ryan; Keyes, Chisholm; Kirk, Lilley, Crossley, Garside, Minchella, Wood. Substitutes: Peltier, Flanagan, Storton, Green.
Workington Town: Mellor; Hambley, Miller, Morris, Rooke; Doran, Forber; Wilkes, Penkywicz, Dickinson, Olstrom, Moore, Scholey. Substitutes: Newton, Curwen, Dawson, Moimoi.