Darragh Lenihan and Dominic Samuel gave the newly-promoted Championship side a two-goal lead heading into half time, and despite Everton introducing £50m signing Richarlison for his debut, they could not find a route back into the match.
Bradley Dack sealed the result once and for all with a third goal 21 minutes from time, leaving new Everton boss Marco Silva now without a win in four pre-season matches since their 22-0 triumph over Austrian minnows Irdning.
The game got off to a quick start with chances at both ends, but Dack fired narrowly wide having been set up by Lenihan and Danny Graham before Tom Davies also missed the target for the Toffees moments later.
The opening goal arrived after only 10 minutes, though, when a short corner was clipped into the box by Richard Smallwood, allowing Lenihan to loop his header over Maarten Stekelenburg and into the far corner.
Blackburn continued to put the pressure on their Premier League opponents as the first half wore on, with Elliott Bennett seeing one effort blocked by Ashley Williams before Dack and Samuel both failed to hit the target on the half-hour mark.
Everton took a while to respond, but they created their best chance of the first half in the 37th minute when Davies threaded a ball through for Gylfi Sigurdsson, who could only scuff his effort into the grateful arms of David Raya.
It proved to be a costly miss for the Toffees as Blackburn doubled their lead just three minutes later, with Dack the creator as he drove into the box and pulled the ball back for Samuel, who slammed his finish past Stekelenburg from 10 yards.
The hosts took a deserved lead into the break and remained unchanged at the interval, whereas Silva made nine outfield subs, including a first appearance in blue for summer signing Richarlison.
The changes appeared to initially have the desired effect for the visitors too, with only a fine save from Raya denying Cenk Tosun from six yards out before Michael Keane missed the target with a headed effort of his own.
Blackburn continued to pose a threat themselves, though, and Bennett forced Stekelenburg into a save before both Lenihan and Dack came close in quick succession shortly after the hour mark.
Dack would not be denied with a little over 20 minutes remaining as he raced on to a loose ball inside the area before finishing past Stekelenburg to all but wrap up the result.
Everton had a number of late chances to reduce the deficit and at least give themselves a consolation goal, but Tosun wasted the best of them by planting another close-range header wide before Nikola Vlasic and Richarlison both also failed to hit the target.
Blackburn ultimately held on to their three-goal lead - and even had a chance to extend it late on when Stekelenburg kept out another Lenihan header - making it back-to-back pre-season wins with just one friendly left before the start of the new Championship campaign.
Everton, meanwhile, will still face Rennes and Valencia before getting their Premier League season underway against newly-promoted Wolverhampton Wanderers.
BLACKBURN: Raya; Nyambe, Lenihan, Mulgrew, Bell; Evans (Travis 83'), Smallwood, Bennett, Dack, Samuel; Graham
EVERTON: Stekelenburg; Kenny (Coleman 46') Robinson (Baines 46'), Williams (Keane 46'), Pennington (Jagielka 46'); Besic (Gueye 46'), Davies (Schneiderlin 46'), Sigurdsson (Dowell 46'); Sandro (Vlasic 79'), Niasse (Richarlison 46'), Mirallas (Tosun 46')