Rovers fall to defeat in difficult conditions at Oakwell.
First-half goals from Devante Cole and Jordan Williams and a second-half strike from Josh Benson was enough to secure all three points for Barnsley at Oakwell.
Rovers made one change to their line-up after Saturday's win over Oxford. Skipper Paul Coutts makes his return, in place of player-coach Glenn Whelan.
The Gas found themselves one goal down in the pouring rain shortly after kick-off. Devante Cole latched onto Callum Styles' through ball, took the ball to the byline and lifted the ball over Belshaw to open the scoring.
Barnsley had their second soon enough. A speculative effort from Jordan Williams took a mean deflection on its way to the goal which completely wrong-footed Belshaw leaving the Rovers 'keeper with no chance.
It was almost a third for the hosts shortly after the second goal. Devante Cole looked to beat Belshaw from a tight angle yet again, but the Rovers stood firm and was able to beat the ball away from the danger.
Rovers manager Joey Barton looked to mix things up for the second-half by making three substitutions. On came Glenn Whelan, Lewis Gibson and Jordan Rossiter to replace Paul Coutts, Antony Evans and Lewis Gordon.
Barnsley added a third ten minutes into the second-half. The ball fell to Josh Benson from around 25-yards-out and the Barnsley No.10's effort fizzed past Belshaw into the bottom corner of the net.
Next up for Rovers is this weekend's visit to the South coast where we play Portsmouth at Fratton Park. (3pm KO)
BARNSLEY: Brad Collins, Jordan Williams, Mads Andersen, Robbie Cundy, Liam Kitching, Callum Styles, Luca Connell, Josh Benson, Luke Thomas, Devante Cole, Jake Aitchison.
Substitutes: Jack Walton, Conor McCarthy, Clarke Oduor, Will Hondermarck, Matty Wolfe, Aiden Marsh, James Norwood.
ROVERS: Belshaw, Hoole, Connolly, Gordon, Evans, Coutts (c), Finley, Collins, Marquis, Anderson, Saunders.
Substitutes: Jaakkola, Kilgour, Gibson, Whelan, Loft, Rossiter, Lawrence.
Referee: Darren Drysdale