Daniel Stendel's side are well beaten in the Sky Bet Championship.
A first half horror show saw the Reds put to the sword by visitors Luton Town at Oakwell.
Goals from former Barnsley midfielder Jacob Butterfield, striker James Collins and Harry Cornick saw the Hatters go in at the break three goals to the good.
It took just two minutes for the deadlock to be broken and it came when neither the 'keeper or defence could deal with a cross from the right and the ball dropped for Butterfield on the edge of the area who fired home with power, left-footed and into the bottom corner.
Three minutes later and the lead was doubled. This time Collins nudged home on the line after fine work from another former Red in James Bree.
There were further chances for Luton, but Matty Pearson and Collins saw headers saved by Sami Radlinger and Butterfield saw another drive blocked on the line by Toby Sibbick.
Nothing came in return from a lacklustre Barnsley before the third goal arrived on the half-hour mark. A set-play from the flank wasn't dealt with and Cornick smashed home from close range for 3-0.
HALF TIME: Barnsley 0-3 Luton Town
Both Dani Pinillos and Mads Andersen were hooked at half time; Ben Williams and Jordan Green introduced.
It was an improved second half showing but it never really looked likely to turn the result around.
Mallik Wilks and Mama Thiam saw Hatters 'keeper Simon Sluga deny them with shots from the edge of the box, before a Wilks header flew a yard wide.
Sibbick then saw his own header - a bullet of a contact - zip a foot wide from a corner.
Bambo Diaby was stretchered off to be replaced by Aapo Halme midway through the half. It looked a bad one.
The Reds did claw a goal back, with 15 minutes left on the clock. Alex Mowatt pulled a ball back from the byline and Wilks was on hand to slam in for 3-1.
Barnsley pushed forward in search for a second goal and the blistering pace of Green caused the Hatters' defence problems as he continued to drive towards the byline or cut inside.
However, the hosts were unable to find a way through a stubborn Luton backline, despite the best efforts of Luke Thomas, whose energy and dynamism didn't go unnoticed by the Oakwell faithful.
Attention now turns to next weekend and a trip to Wigan Athletic.
REDS XI: Radlinger, Sibbick, Andersen (Green, 46), Diaby (Halme, 67), Pinillos (Williams, 46), McGeehan, Mowatt, Thomas, Bähre (c), Wilks, Thiam.
Not used: Collins, Oduor, Chaplin, Schmidt.
LUTON XI: Sluga, Bolton, Bradley (c), Pearson, Bree (Galloway), Butterfield, Shinnie, Tunnicliffe, Cornick (Lee), Collins, LuaLua (Mpanzu).
Not used: Shea, Moncur, Brown, Jones.
