The Tykes took a 38th lead, before Papa Bouba Diop (pictured) equalised for Richard Beale’s Blues side right on the stroke of half time.
Although the game was sometimes lacked quality, the commitment shown by both sides more than made up for it.
Barnsley fashioned the better openings in the early stages. Danny Rose saw his shot rebound back off David Lucas’ upright, and then the Blues stopper did well to turn Jordan Clark’s effort behind for a corner.
But it was Blues who should have taken the lead on 17 minutes and would have done so had Barnsley keeper Lukas Lidaveicis not denied Diop from close range.
Blues were forced into a premature change just after the half-hour mark when Lucas was taken ill and he was replaced by youngster Nick Townsend.
Townsend almost immediately conceded after he was rounded by Clark, but fortunately Ben Gordon was in the right place to put in a terrific block with an empty net beckoning for the Barnsley man.
But Barnsley weren’t to be denied minutes later as Rose’s cross found Jordan Clark at the far post and he slid the ball home from just a few yards out
Their lead lasted less than ten minutes as Blues hit back when Diop stabbed the ball home following a goal mouth scramble.
Beale’s side started the second half brightly and Reece Hales was desperately unlucky to see his brilliant curling shot from almost 30 yards out hit the post and bounce back into play.
However, the visitors responded well and twice saw good chances deflected wide for corners.
As the game entered its closing stages Blues looked the more likely side to snatch all three points with Nathan Redmond, Reece Hales and Morgaro Gomis all going close.
Then as the game entered stoppage time Mitch Hancox showed great energy to run almost the full length of the pitch before being denied by Lidaveicis at full stretch.
Full-time: Blues U21s 1 Barnsley U21s 1
Blues: David Lucas (Nick Townsend, 33), Will Packwood, Ben Gordon, Emmitt Delfouneso, Mitch Hancox, Papa Bouba Diop, Eddy Gnahore (Ryan Higgins, 63), Morgaro Gomis, Callum Reilly, Nathan Redmond, Reece Hales Marcel Henry-Francis, 73).
Subs not used: Josh Hawker, Jack Deaman.