The match was billed in some quarters as a shoot-out between Blackburn striker Jordan Rhodes and free-scoring Burnley counterpart Charlie Austin, and the latter found Rovers goalkeeper Paul Robinson in inspired form.
Robinson also did superbly to thwart Martin Paterson and, having weathered the storm, Rovers drove forward after the restart.
They broke through in the 65th minute when Rhodes caught Burnley's back line flat-footed and found space to head home Mauro Formica's right-wing cross.
But it was another striker, Wales international Vokes, who brought Turf Moor to its feet, planting a free-kick from fellow substitute Junior Stanislas beyond Robinson three minutes after replacing Chris McCann.
As the match got underway, Austin looked to add to his remarkable 21-goal haul this season when he got on the end of Kieran Trippier's right-wing cross, but Scott Dann did well to block the shot.
Ross Wallace caught the Rovers defence napping with a cleverly-worked short corner in the 18th minute. Robinson beat away his near-post effort and Clarets captain Jason Shackell thrashed the rebound over.
Wallace stung Robinson's palms from distance before turning provider with a searching, deep cross that Austin headed back the way it came to draw a magnificent stop from the former England goalkeeper.
It was a save he bettered in the 41st minute, tipping Paterson's shot on the turn from 25 yards away from his bottom corner at full stretch.
Somehow the Rovers goal remained intact until the interval and they spent considerably more time in the Burnley half on the resumption, but Colin Kazim-Richards shanked aimlessly over from distance.
After Danny Murphy and Dann combined to muscle Austin out of the decisive touch to a Wallace centre, Kazim-Richards came much closer as the hour approached - spinning a shot narrowly wide with the outside of his right foot from the edge of the area.
Blackburn were undeniably in the ascendancy and the next time Formica crossed from the right Rhodes stole in to glance beyond Grant.
Controlled and composed periods of possession appeared to have Rovers playing out the win in relative comfort until Vokes' late intervention.
The former Wolves man's physical presence had the Blackburn defence reeling, but when another header flew over the bar in stoppage time it meant Burnley's 33-year wait for derby glory had to continue.