Malky Mackay, Cardiff's manager, lamented his side's inability to convert their numerous chances into goals as Stephen Foster's equaliser deep in added time delayed their bid to finally book a spot in the Premier League.
The runaway Championship leaders looked set to take another giant leap towards promotion courtesy of defender Ben Turner's second-half strike.
But, with just four seconds left, relegation-threatened Barnsley grabbed a precious equaliser through Foster to temporarily halt Cardiff's mission of reaching the top-flight for the first time since 1962.
Mackay said: "We should have been more clinical but [overall] I was delighted with the way we played.
"We dominated them, had chances and should have had the game finished. At 1-0, anything can happen and a freak goal did happen.
"On another day we would have got the three points. But we are a point better off than before the game, and point closer to the total to get the prize that everyone at the football club wants."
Cardiff's fans vented their anger towards the referee Fred Graham for eventually playing an additional seven minutes. But Mackay, whose side now lie nine points ahead of third-placed Watford with five games remaining, insisted he received an acceptable explanation from the Essex official following the final whistle.
Mackay added: "He said the extra-time beyond five minutes was for Kevin McNaughton going down. When they scored there was four seconds to go. I'm absolutely fine with the referee."
For Barnsley, this point was extremely valuable as Foster deflected Stephen Dawson's effort past David Marshall to help the Tykes edge further away from the drop zone.
The Barnsley manager, David Flitcroft, said: "It was more than a point for us. My players went 97 minutes against the champions-elect and I can't ask for anymore."
Cardiff City (4-5-1): Marshall; McNaughton, Barnett, Turner, Taylor; Smith (Conway, 80), Gunnarsson, Mutch, Kim (Whittingham, 68), Bellamy; Mason (Helguson, 58). Substitutes not used Lewis (gk), Gestede, Noone, Nugent.
Barnsley (4-4-2): Steele; Wiseman, Foster, Hassell, Kennedy; O'Brien Cywka, 61), Perkins, Dawson, Mellis (Dagnall, 70); Harewood (Scotland, 67), O'Grady. Substitutes not used Alnwick (gk), Jones, Rose, Patterson.
Referee F Graham (Essex).