Goals from Rovers' deadly strikeforce maintained the club's unbeaten start to the season.
Jordan Rhodes and Nuno Gomes did the damage once again with a goal in each half as Rovers claimed their third home win in succession.
Rovers were made to work hard by an enterprising Barnsley side who fully deserved their 32nd minute league when Jacob Mellis fired the visitors in front.
The home side huffed and puffed but it was a moment of class from record signing Jordan Rhodes that saw Rovers level on the stroke of half time when from Morten Gamst Pedersen's knockdown Rhodes swivelled superbly to lash home.
Rovers improved in the second half but the game appeared to be heading towards a hard fought draw until two substitutes combined to clinch all three points five minutes from time.
The goal was made in Portugal as Fabio Nunes showed trickery and quick feet to send a searching ball into the box to where Nuno Gomes arrived to fire into the back of the net.
The win keeps Rovers at the top of the table with Middlesbrough up next at Ewood on Friday.
Despite the 5-3 win that took Rovers to the top of the table at the weekend, Steve Kean made four changes for the visit of Barnsley.
With injury ruling out Markus Olsson and Gael Givet, their places were taken by Martin Olsson and Grant Hanley, a first start of the season for the elder Olsson.
Also getting the nod in the starting eleven were Mauro Formica and Ruben Rochina, they replaced Bruno Ribeiro and Nuno Gomes who both dropped to the bench.
For the visitors, managed by former Rovers defender Keith Hill, they named an unchanged eleven from the side that had earned a creditable draw with Blackpool at Oakwell on Saturday.
The game started at a lively open pace but it was Barnsley who were soon into their stride.
Just five minutes in and Paul Robinson was called upon to make a crucial save when following an error from Grant Hanley Jacob Mellis stole into the area to shoot across goal, Robinson got a hand to the ball to push it aside and Bradley Orr was quickly in place to block Craig Davies on the follow-up.
Rovers, however, didn't take heed of that early warning as Keith Hill's Tykes continued to force the pace. Paul Robinson had to be brave to save at the feet of Chris Dagnall, whilst Jon Stones hooked a ball over the bar after a corner kick fell to the young defender.
At the other end chances for Rovers were few and far between, Jordan Rhodes fired wide from a narrow angle after Ruben Rochina had robbed Dawson, and Martin Olsson stung the gloves of Ben Alnwick with a fiercely struck effort.
Eventually the opening goal came and it was no surprise that it came from the team from red. The goal started on the left with Davies and Tomasz Cywka combining to tee up Chris Dagnell and he flicked the ball into the path of Jacob Mellis and the former Chelsea youngster lashed home past Robinson. It was the least the visitors deserved.
Ruben Rochina went close with a header from a Pedersen free-kick, but right on the stroke of half-time Rovers were level with a quality goal from a quality striker.
Bradley Orr sent a free-kick to the back of the area where Morten Gamst Pedersen nodded to the edge of the six yard box, Jordan Rhodes still had plenty to do but with his back to goal the record signing swivelled and hammered the ball beyond Alnwick.
Neither side made changes at the break as Rovers started on the up at the beginning of the second half. Just three minutes in and Ruben Rochina went close with a fizzing effort that flew narrowly over the angle of post and bar.
But Barnsley were patient, they played calm composed football, putting Rovers under pressure with a series of corners that they struggled to deal with.
Both sides sent on strikers in a bid to claim the win, Barnsley with Marlon Harewood, Rovers with Nuno Gomes, and it was Harewood who wasted a great chance when he fired wide after Kelvin Etuhu capitalised on a Scott Dann error.
Under the watching eye of Scotland boss Crag Levein, Jordan Rhodes was a constant threat and he came close to grabbing his second of the game when he turned well to fire goalwards but Alnwick was equal to his efforts. Moments later the former Huddersfield man held off Scott Wiseman but the Ben Alnwick in the Barnsley goal was there to deny the Scottish international.
As the game entered the final ten minutes it looked like it would head towards a hardworking draw between the two sides, but our boys from the bench had other ideas.
With five minutes to go Fabio Nunes picked up a ball from Martin Olsson and he whipped over a sensational low cross to which his countryman Nuno Gomes needed no second invitation, arriving perfectly to grab his fourth goal in as many games for the club and in doing so ensuring all three points once more.
It was tough on Barnsley as they had worked tirelessly throughout, but Rovers just had that extra bit of class when and where it counted.
ROVERS: Robinson, Orr, Hanley, Dann, Martin Olsson, Formica (sub Lowe 90 mins), Murphy (c), Etuhu, Pedersen (sub Fabio Nunes 80 mins), Rochina (sub Nuno Gomes 66 mins), Rhodes.
Subs not used: Kean (GK), Henrique, Dunn, Ribeiro.
Goals: Rhodes 45 mins, Nuno Gomes 85 mins.
BARNSLEY: Alnwick, Golbourne, Foster, Dawson, Davies (sub Harewood 65 mins), Dagnall (sub Etuhu 70 mins), Wiseman (c), Cywka, Mellis, Cranie, Stones (sub Perkins 73 mins).
Subs not used: Steele (GK), Done, Digby, Noble-Lazarus.
Goals: Mellis 32 mins.