Daryl Powell reshuffled his Leeds team to find the winning formula against a side they had previously beaten only once in seven seasons of Super League.
Leeds followed their Challenge Cup win over Bradford in February by halving their local rivals lead at the top of the table to two points, with Powell's imaginative changes to his back division proving decisive.
Ben Walker was moved to full-back for the first time in his career and thrived there, while Kevin Sinfield stiffened the midfield defence and played a key role in seizing the initiative either side of half time.
Leeds were trailing 10-0 to a Tavita Vikona try and three goals from Paul Deacon after a half hour more notable for a mass fracas and the sin-binning of Adrian Vowles and James Lowes when Sinfield broke through for his side's first points.
Two minutes later, he almost did the same again, this time getting the ball out of the tackle for Willie Poching, whose path was blocked but who improvised by jumping over his team-mate to touch down. Walker's two goals gave Leeds a lead that had looked unlikely a few minutes earlier.
Ryan McDonald continued the good work after the break, using his size to force his way over the line and Leeds were in a winning position when Tonie Carroll surged over from a scrum soon after.
Bradford could not get going, although their coach Brian Noble, refused to blame the virus that had swept through the camp during the week. "You can't play rugby league if you keep giving the ball away," he said. "We weren't very smart in the second half and we didn't show any patience or composure."
The Bulls did repair some of the damage when Robbie Paul dummied one way and darted the other to cut the margin to eight points, but two more goals from Walker kept them in control and Stuart Fielden's late try could not swing it back in Bradford's direction.
Powell could reflect on an experiment that had worked perfectly: now he has to decide whether to persist with it.
"It shows it was not a one-off," he said. "We have been criticised for not beating the top teams but I think we've made a few critics eat their words tonight.
"I think Ben will be an outstanding full-back but whether we do it consistently, I don't know.
Leeds Rhinos: B Walker; Calderwood, Carroll, Senior, Cummins; Sinfield, Sheridan; Ward, Diskin, Barrie McDermott, Hay, Adamson, Vowles. Substitutes used: Burrow, Poching, Jones-Buchanan, McDonald.
Bradford Bulls: Withers; Vaikona, Costin, Gilmour, Vainikolo; Paul, Deacon; Vagana, Lowes, Brian McDermott. Peacock, Gartner, Forshaw. Substitutes used: Pryce, Anderson, McAvoy, Fielden.
Referee: R Smith (Castleford).Reuse content