A second half strike from Adam Armstrong proved to be enough for a 1-0 win over neighbours Rotherham United.
Armstrong struck the winner on 70 minutes to fire Barnsley to within a point of the play-off places.
Matty James made his Reds debut in midfield and Marc Roberts took over the captaincy following the sale of Conor Hourihane while Marley Watkins, who has asked to leave Oakwell, was named as right winger.
New signing Alex Mowatt missed the deadline to play after joining from Leeds United on Friday afternoon.
Gethin Jones played right back with Aidy White in his natural left back position.
The home side started the brighter with Danny Ward just inches away from getting on the end of Jon Taylor's cross.
Barnsley responded with Ryan Kent cutting inside of Darnell Fisher and then lashing wide.
Taylor was then denied a shot on goal by a good tackle from Angus MacDonald.
The defender then made an even better block to divert Ward's goal-bound effort from going in.
White then came extremely close to scoring against his former club.
The left back was slipped in neatly by Watkins but dragged his effort wide of the far post.
Rotherham were then cut open by a pass from Roberts but Armstrong's lobbed effort clipped the crossbar on its way over Richard O'Donnell's goal.
Joe Mattock hit the woodwork at the other end with a drilled 25-yard effort.
The Millers started the second period on top with Ward going close with a chipped effort.
Armstrong then struck an effort wide after being set up by Kent.
Rotherham had the next big chance but Jerry Yates' header was straight at Adam Davies.
Barnsley went in front on 70 minutes when Kent slipped in Armstrong with a quality pass and the loanee striker beat O'Donnell coolly.
Watkins almost made it two in the closing stages with a powerful drive on the angle which took a deflection to go just wide.
Rotherham United: O'Donnell, Fisher (Allan 77), Wood, Belaid (Kelly 25), Mattock; Taylor, Smallwood, Vaulks, Forde (Bray 86), Yates, Ward.Unused: Bilboe, Adeyemi, Warren, Blackstock.
Barnsley: Davies, Jones, MacDonald, Roberts, White (Evans 60), Watkins, Scowen, James, Kent (Hammill 86), Bradshaw, Armstrong (Williams 81).Unused: Townsend, Jackson, Moncur, Payne.
Referee: Keith Stroud (Hampshire).
Attendance: 11,050 (2,601 from Barnsley).
