Rovers signed off their home campaign in style as they won out in an entertaining game that saw seven goals and seven different scorers.
A fast start saw the hosts go 2-0 up inside the opening six minutes through strikes from Ben Brereton and then Adam Armstrong.
But Reading hit back through John Swift's pinpoint free kick to make things interesting and send Rovers into half time with a slender advantage.
Rovers continued to showcase their attacking qualities early into the second half, with Joe Rothwell firing home a second successive home goal to put Rovers 3-1 up.
Reading weren't finished though and managed to find two quickfire goals through headers from Sam Baldock and Yakou Meite to level things up.
And just as it looked as if Rovers would sign off at Ewood Park with a frustrating draw, Sam Gallagher won it for Rovers in the final three minutes to narrowly bag the points for Tony Mowbray's men.
Hayden Carter made his professional debut as one of five alterations from the team that started against Millwall just a few days earlier.
Carter started at centre back in place of Tosin Adarabioyo, who wasn't included in the matchday squad.
In a back four made up entirely of Academy graduates, Ryan Nyambe was another change as he came in for skipper Elliott Bennett.
Elsewhere, there were starting berths for Rothwell, Lewis Holtby and Brereton, with the trio coming in for Dominic Samuel, Danny Graham and Stewart Downing.
The visitors made two alterations to the side that suffered a home defeat to Middlesbrough last time out, with Chris Gunter and Omar Richards earning recalls.
It took only three minutes for the returning Brereton to make his mark on the game and grab his first of the season by beating Rafael Cabral in the visiting goal.
After working a yard in the box, his left footed effort deceived Reading's Brazilian stopper and nestled nicely into the back of the net for his second goal in blue-and-white.
It took just three minutes more for the second of the day to arrive, and it came via a familiar source as Armstrong lashed low into Cabral's bottom left-hand corner for his 16th goal of the campaign.
However, despite the good start, Mark Bowen's Royals battled back and pulled one back on the 15 minute mark through midfield playmaker Swift.
Despite being 30 yards from goal, the midfielder managed to send his free kick over the Rovers wall, beyond Walton and into the bottom left-hand corner.
The goal breathed a bit of life into the Berkshire side, with Tom McIntyre glancing a Swift corner just past Walton's post from close range.
Rovers were looking rampant when they went forward, with Armstrong firing over the upright before Cabral got in the way to deny Brereton's attempted dink just before the break.
Mowbray's men were certainly worth the half time lead and that was what they achieved going into the interval thanks to the two early goals.
Rovers continued in the same vein in the second half and Rothwell made it back-to-back home goals with a deflected effort that squirmed past Cabral and in just 11 minutes after the interval.
The dangerous Armstrong went close to adding to his and Rovers' tally, but his curled attempt was straight down the throat of the Reading goalkeeper.
However, just as it looked like Rovers would go on and record a big scoreline, Baldock emerged off the bench to make an impact for Bowen's boys.
A cross from the left found the head of the substitute, who glanced a header beyond Walton just five minutes after entering the action.
And from nowhere two goals became three for the Royals as Meite made it 3-3 with 22 minutes remaining.
Garath McCleary's cross was stood up perfectly for the Ivorian striker, who planted a header into the corner to level things up.
The Royals went close to turning the score around soon after, with only a vital touch from Carter deflecting Michael Olise's curled attempt onto the post and behind for a corner.
Just as it looked as if the final home encounter would end all squad, Gallagher rose at the back post to nod past Cabral after fellow substitute Harry Chapman picked him out with a pinpoint cross from the left.
The cherry on the top of the cake right at the death, but the debuting Jack Vale crashed a shot against the bar before the full time whistle was blown on the game and Rovers' home campaign.
Rovers: Walton, Nyambe, Lenihan (c), Carter, Rankin-Costello, Travis, Johnson (Davenport, 69), Rothwell (Chapman, 78) Holtby (Buckley, 69), Armstrong (Vale, 78), Brereton (Gallagher, 69).
Unused subtitutes: Leutwiler, Downing, Bennett, Magloire.
Goals: Brereton, 3, Armstrong, 6, Rothwell, 56, Gallagher, 87
Reading: Rafael, Gunter, Morrison, Rinomhota, Swift (c) (Osho, 83), McIntyre (Moore, 36), Meite, Olise, Blackett (McCleary, 59), Richards (Obita, 59) , Puscas (Baldock, 59).
Unused substitutes: Walker, Miazga, Boye, Araruna, Osho.
Goals: Swift, 15, Baldock, 64, Meite, 68.