Two goals from Dwight Gayle consigned Barnsley to a third straight defeat.
Gayle got into double figures for the season with a second half brace that ensured Newcastle took the points on a noisy night at Oakwell.
Captain Conor Hourihane was deemed fit enough to play after he missed the weekend game against Fulham with a calf injury.
Adam Jackson was also picked for his debut and James Bree came in to the starting eleven with Cole Kpekawa, Angus MacDonald and the suspended Josh Scowen out. Ryan Williams made a return to the bench following a long spell out.
Barnsley had the first effort on goal when Hourihane latched on to some defensive indecision but his dragged shot flew wide of the post.
Newcastle's first opportunity came when the league's top scorer Gayle played a neat flick to Matt Ritchie whose cross was just behind Gayle who could only flick it acrobatically over the bar.
Ritchie then had a shot blocked from Jonjo Shelvey's half cleared free kick.
At the other end, James Bree whistled a shot wide of goal after Hourihane's free kick hit the Newcastle wall.
Sam Winnall then shot straight at Newcastle 'keeper Karl Darlow with a free kick from the edge of the box.
Gayle pounced for the game's opener on 48 minutes.
A corner from Ritchie was not properly cleared and Gayle responded at the back post to loft the ball beyond Davies.
The Reds responded with Sam Morsy cutting inside and shooting just over the bar.
Marc Roberts then found his central defensive partner Jackson with a long throw but the defender headed wide of goal after rising highest in a crowd of bodies.
Gayle sealed the victory from Ritchie's pass on 68 minutes. The striker raced onto the ball and lofted it over the advancing Adam Davies.
The striker almost got his hat-trick when he got a touch on Shelvey's low cross into the box but it was clawed out by Davies and he made the 'keeper work again with a volley from Darlow's long ball.
The Reds came close to a late consolation but substitute Tom Bradshaw could not get a touch on Ryan Kent's driven cross.
Barnsley: Davies, Bree (Kpekawa 83), Roberts, Jackson, Yiadom, Kent, Morsy, Hourihane, Hammill (Lee 71), Winnall, Watkins (Bradshaw 71).Unused: Townsend, MacDonald, Bird, Williams.
Newcastle: Darlow, Anita, Clark, Lascelles, Dummett, Ritchie (Atsu 82), Hayden, Diame (Colback 90+2), Shelvey, Gouffran, Gayle.
Unused: Sels, Lazaar, Perez, Yedlin, Mitrovic.Referee: Paul Tierney (Lancashire).Attendance: 18,597 (5,501 from Newcastle).
