Luton Town see off the Reds at Oakwell for a third year running.
On a cool summer's evening, Barnsley came up short to lose their first game of the 21/22 Sky Bet Championship campaign, succumbing to Amari'i Bell's fourth minute strike.
The Reds actually began the first half quite brightly, dominating the very early exchanges and when Romal Palmer looked to be hauled down in the box, referee, Oliver Langford waved away the protests.
Immediately up the other end, a nothing ball over the top bamboozled Michał Helik, the defender misjudged his header allowing his man to get to the ball right-hand side, he stuck over a low cross that everyone missed inside the penalty area, all except Amar'i Bell, the left full-back arrived on the angle of the box to rifle home a low finish into the near corner to give the visitors an early lead.
Palmer would later test Hatters 'keeper Simon Sluga with an effort from an acute angle, but it was a lethargic and lacklustre first half Reds performance, who will have been grateful for the away side not taking advantage and thus, taking the game away from them.
Callum Brittain stung the goalkeeper's hands with a snapshot just before the break, but Barnsley went into the interval knowing they had much to improve on if they were to maintain their unbeaten start to the season.
HALF-TIME: Reds 0-1 Luton
The second period was played almost exclusively in the Luton half with the Reds continually pushing back the away side in search of an equaliser. But no matter how hard they tried, Markus Schopp's outfit were unable to break down the door.
Brittain dragged an effort just wide from the right side of the box, substitute Devante Cole couldn't quite touch home a low cross, but clear-cut chances were hard to find on a disappointing evening for Barnsley.
A couple of opportunities did present themselves late on, with crosses cleared only as far as the edge of the box, but first Josh Benson volleyed over and then Callum Styles had a slightly easier chance, again pouncing on a poor clearance, but he also blazed over from 12 yards.
The visitors were happy to soak up the pressure and clear their lines, occasionally having joy on the counter, and with the Reds unable to show any kind of clinical edge, the Hatters left Oakwell, for the third year running, with all three points.
FULL-TIME: Reds 0-1 Luton
Collins, Brittain, Sibbick, Helik, Kitching, Styles, Palmer (Halme), Benson, Woodrow, Frieser (Adeboyejo), Oduor (Cole).
Unused: Walton, Moon, Miller, B.Williams.