Daniel Stendel’s first experience at Oakwell ended in defeat in a five-goal thriller to West Brom.
The new Barnsley boss oversaw a 3-2 loss, from 2-0 up, to the Championship club.
Former Reds centre-back Darren Moore orchestrated a fine comeback win.
Stendel gave 18 players a run-out as he gears up towards the start of the club’s League One campaign.
Earlier, the Reds unveiled their new black away strip, which the squad donned for their first home friendly of their pre-season.
They came firing out of the blocks with Brad Potts powering wide after Lloyd Isgrove broke through the defence early on. But they were not to be denied as Isgrove out-jumped keeper Jon Bond to head home Alex Mowatt’s cross.
And five minutes later the lead was doubled as centre forward Kieffer Moore guided Dani Pinillos’ pinpoint cross past Bond via the post.
It was almost three later, with sought-after striker Tom Bradshaw missing the target after Mamadou Thiam dazzled his way into space to put in a decent cross.
Young stopper Jack Walton pulled off a top save to keep the visitors at bay, before a fantastic goal-line block by Ethan Pinnock.
However, the Barnsley defence was broken just before the internal with Hal Robson-Kanu scoring the third header of the game by diverting Chris Brunt’s free-kick beyond Walton.
And the Baggies were level seconds after the restart as the Reds were caught napping.
Pinnock was caught in possession in his own half, with James Morrison taking advantage with a super strike.
And the Reds were behind five minutes after being pegged level with Dimitri Cavare slicing into his own net.
Brad Potts forced a brilliant stop out of Bond as the Reds sought an equaliser. Right at the death Moore missed a glorious chance to level where he hit an effort over after linking up with Bradshaw.
Barnsley: Walton, Cavare (McCarthy, 73), Pinnock, Lindsay (Williams, 82), Pinillos (Jackson, 82), Isgrove (Moncur, 69), Mowatt (Bird, 73), Potts (McGeehan, 73), Thiam (Adeboyejo, 69), Moore, Bradshaw.