Former Hull City defender Bradley latched onto Graham Carey’s corner and headed powerfully home to settle proceedings as second-placed Argyle cut Rovers’ advantage to three points.
The goal inflicted a first home league reverse upon Rovers in 23 games since Blackpool triumphed on March 28 of last year.
Rovers, unchanged for a fifth successive game, had the better of a fascinating first half, with the half-time interval arriving at a timely juncture for Argyle, who were starting to creak a little just before the break.
The hosts went mighty close to drawing first blood on two occasions leading up to the interval, with a combination of Luke McCormick and Oscar Threlkeld blocking a goalbound drive from James Coppinger after good work by Mathieu Baudry and Tommy Rowe.
McCormick, given merciless stick from the home fans in the Black Bank, also performed heroics on 39 minutes, making a miraculous one-handed reaction save to somehow keep out John Marquis’s point-blank header after a fine run and cross by the impressive Matty Blair.
Rovers had the better of proceedings in a half which showcased the tactical acumen of both sides, with early appeals for a penalty turned down when Rowe fell under pressure from David Fox.
With a game plan based upon soaking up Rovers’ pressure and counter-attacking when the chance arose, Argyle were largely inhibited as an attacking force in the first half, with some rare enterprise seeing Matthew Kennedy embark on a mazy run before dragging his low shot wide.
Most of the action was at the other end, with Marquis heading wide under pressure following Rowe’s centre, while McCormack gathered an audacious lob from Conor Grant shortly after his outstanding reaction save to deny Marquis.
After surviving a few scares in the run-up to the break, Plymouth rallied on the restart with Andy Butler heading narrowly wide of his own net following Gary Miller’s teasing cross and moments later, Argyle forged a breakthrough.
The unmarked Bradley headed home in emphatic fashion at the far post following Graham Carey’s deep corner.
Carey then drilled a great chance to double Plymouth’s advantage after breaking clear and firing wide before Jake Jervis was also off target with the opener rocking Rovers.
They eventually regrouped, with Coppinger firing over when well placed before McCormick again performed wonders to keep out the Rovers’ veteran’s downward shot.
But it was not the prelude to an assault from Rovers in the final twenty minutes, with professional Plymouth seeing the job out to claim a big three points, with the only scare coming when Jakub Sokolik made a key block to deny Rowe.
Doncaster Rovers: Lawlor; Blair, Baudry, Butler, Alcock (McCullough 55); Mason (McSheffrey 80), Grant, Rowe, Coppinger; May (Williams 73), Marquis. Unused substitutes: Marosi, Middleton, Evina, Lund.
Plymouth Argyle: McCormick; Miller, Sokolik, Bradley, Threlkeld; Sarcevic, Fox; Jervis, Carey (Blissett 90), Kennedy (Songo’o 74); Spencer (Taylor 81). Unused substitutes: Sawyer, Slew, Donaldson, Dorel.
Referee: O Langford (West Midlands).
Attendance: 7,414 (900 Plymouth supporters).