The hosts had the better of the first half, with James Bree’s rasping 25-yard drive and Conor Hourihane’s volley the best of the early chances for either side.
Dwight Gayle’s attempted scorpion kick and free kick failed to trouble Adam Davies in the Reds goal with Sam Winnall’s free kick the last action of the first half.
The visitors edged ahead within four minutes of the restart as Gayle pounced on a loose ball in the area to fire past Davies but Sam Morsy and Adam Jackson came close in reply for the Reds.
Gayle increased his and Newcastle’s tally when he lobbed Davies from outside the area and Davies had to be alert to stop the Newcastle striker increasing his tally.
Substitute Tom Bradshaw was unable to connect with Ryan Kent’s low cross to snatch a consolation for the hosts late on, as the Reds were applauded off by over 18,000 fans.
Inside a packed Oakwell, both sides found it difficult initially to carve out chances in the opening exchanges, with neither side able to break the other down.
Adam Davies was the first goalkeeper called into action 10 minutes, competently dealing with Jonjo Shelvey’s free kick by pushing it away from danger.
The Reds did fashion the first opening just before the quarter hour mark as Marley Watkins’ delicate header was volleyed inches wide by Conor Hourihane.
Newcastle began to grow into the match and had their first clear opening on 23 minutes when Dwight Gayle’s audacious scorpion kick from Matt Ritchie’s delivery flew just over the crossbar.
In reply, Hammill was sent sprawling on the edge of the area giving the Reds a free kick. Hourihane fired straight into the wall but the rebound was
Hourihane was the first name into the book for a handball after Shelvey’s attempted pass struck him but Davies comfortably caught Gayle’s ambitious free kick.
Sam Winnall drew a foul from Jamaal Lascelles on the edge of the area, which resulted in a yellow card for the Newcastle man and gave the Reds a shooting chance 20-yards from goal.
Winnall sized up the opportunity but found Karl Darlow in fine form to keep him out while Mohamed Diame headed the final chance of the half over from a Newcastle corner.
Within four minutes of the restart, the visitors took the lead as a Newcastle corner was not properly cleared and as the ball sprung loose, Gayle pounced to prod home his ninth league goal of the season.
Barnsley almost levelled within a matter of minutes as Sam Morsy unleashed a 30-yard rocket from the edge of the area that flew just over the crossbar.
Reds debutant Adam Jackson also came close to levelling the scores on the hour, meeting Marc Roberts’ long throw but flicking the effort just past the upright.
Paul Dummett fired a left-footed half-volley just over the top but the visitors doubled their lead in the 69th minute as Gayle raced onto a chipped pass and lobbed the onrushing Adam Davies from just outside the area.
Paul Heckingbottom introduced Tom Bradshaw and Elliot Lee for Adam Hammill and Marley Watkins in search of a reaction and the Reds stepped up their attacking intent again.
Jonjo Shelvey hacked down Winnall as he charged down the left while Diame headed wide under pressure from James Bree for the Magpies.
Davies made two excellent saves to prevent Gayle completing his treble, first getting down well to deny him stabbing home Shelvey’s free kick and then getting down smartly to stop him volleying in from outside the area.
Cole Kpekawa was introduced for the final seven minutes in place of Bree while Bradshaw almost snatched a consolation in the final minute but was unable to connect with Ryan Kent’s low cross.
Reds: Davies (GK), Bree (Kpekawa, 83’ ), Roberts, A. Jackson, Yiadom, Kent, Morsy, Hourihane, Hammill (Bradshaw, 71’ ), Winnall, Watkins (Lee, 71’ ).
Subs: Townsend (GK), MacDonald, R. Williams, Bird.
Newcastle: Darlow, Anita, Clark, Lascelles, Dummett, Ritchie (Atsu, 82’ ), Hayden, Shelvey, Gouffran, Diame (Colback, 90+1’ ), Gayle.
Subs: Sels (GK), Lazaar, Perez, Yedlin, Mitrovic