The Reds dominated the match for large periods but, once again, failed to convert their chances and managed just one shot on target, which came in the opening 10 minutes.
An energetic start from the hosts saw the game’s first chance fall to Josh Benson, who was one of four changes to the side beaten 1-0 by Bournemouth on Saturday, but his half-volley from the edge of the box was comfortably saved by Alex Smithies.
The best chance of the first half fell to striker Devante Cole on 35 minutes when he fired wide after Callum Styles stole possession 20 yards from goal.
A better option would have been to pick out an unmarked team-mate with the goal at his mercy, but the out-of-form striker – without a league goal since October – took the shot on.
Barnsley boss Poya Asbaghi handed a start to new signing Domingos Quina, with the Reds’ other new recruit, Amine Bassi, named on the bench.
Portugese youth international Quina, signed on loan from Watford, demonstrated his eye for a pass from the centre of the park and looked to get forward whenever in possession on a decent debut which lasted just over an hour before he was replaced by Carlton Morris.
A rare Cardiff attack early in the second half saw ex-Rotherham midfielder Will Vaulks get into an altercation with a ball boy.
The youngster had hid a towel under his jacket which was being used to dry the match ball before the Cardiff man’s trademark long-throws.
Another comic moment saw Smithies concede a needless corner after failing to control a simple back pass from Mark McGuinness on 71 minutes, much to the delight of the Ponty End.
The keeper was to have the last last though as his goal-kick moments later saw Cardiff substitute and debutant Uche Ikpeazu beat Michal Helik to the ball before holding off the challenge of Mads Anderson to poke the ball past Brad Collins in the Bluebirds’ first effort on target.
Asbhagi rolled the dice with a double switch in response, which saw Aaron Leya Iseka and Bassi replace Benson and Liam Kitching with 15 minutes to play.
Numerous crosses were delivered into the box in the closing stages but, as has been the case all too often for the division’s lowest scorers this season, no-one in a Reds shirt was there to convert.
Cole again should have done better in injury time after he met Bassi’s free-kick at the back post, but headed the ball into the side netting.
Leya Iseka thought he had levelled at the death when he fired from close range following Callum Styles’s pass, only for the offside flag to be raised with the forward already celebrating with fans.
The Bluebirds subsequently held on for their first clean sheet in 26 league matches.
To make matters worse, Barnsley’s assistant coach Joseph Laumann was at the centre of a brawl involving players and staff in the tunnel after the full-time whistle when he shoved Cardiff manager Steve Morison.
Moments earlier Laumann had to be held back by his colleagues after trying to confront Morison in his dugout, with referee Geoff Eltringham producing a yellow card.
A fifth straight defeat means Barnsley remain eight points from safety and without a win in 12 league outings.