Barnsley were knocked out of the FA Cup in the first round by non-league Altrincham on Saturday.
The hosts went ahead 60 seconds into the second half and hung on to win against a disjointed Reds side who had no respite from their struggles in League One in which they have lost seven in a row.
Head coach Lee Johnson was boosted by the returns from injury of Marley Watkins – into the side for Michael Smith who could not play as part of his loan deal from Swindon – and Conor Hourihane who was on the bench.
Youngster George Maris also came into the starting line-up for Lloyd Isgrove who had a shoulder injury and dropped to the bench. Johnson persisted with the 4-3-3 system he used at Coventry with Maris and Watkins partnering Sam Winnall in a front three.
National League side Altrincham were the better team for most of the first half. Reds goalkeeper Adam Davies tipped a 25-yard shot from Jake Moult over the bar then the same player blazed over from inside the box after the visitors could not clear a corner.
Barnsley improved as the interval approached and Winnall's shot from a tight angle on the right of the box was turned behind for a corner. But the Reds had struggled to make their superior status in the leagues count and the hosts had easily matched them.
Altrincham took the lead exactly one minute into the second half. Ben Pearson lost the ball in his own half and Ryan Crowther's shot was not held by Davies so Damian Reeves could tap into the empty net from inside the six yard box.
Johnson then made a triple substitution with Hourihane, Isgrove and Conor Wilkinson coming on for Maris, Marc Roberts and the injured Josh Scowen. The changes made an impact as Wilkinson had a shot deflected into the goalkeeper's arms after a penalty area scramble then Hourihane's 25-yard free-kick clipped the bar. Wilkinson then missed a glorious chance as he volleyed wide inside the box with the goal gaping after a cross was cleared straight to him.