Barnsley, having been comfortably the better side in the first half, had led 1-0 at the break but the Welsh strugglers, seemingly destined for relegation after being deducted 10 points for falling into administration, turned the match on its head.
Their fightback was inspired by midfield maestro Darren Ferguson. He levelled the scores on 58 minutes with a clinical near post finish from a pin-point right-wing cross.
Then on 64 minutes, Ferguson got on the end of a Juan Ugarte cross and although his shot was heading away from goal, it fell to the feet of striker Chris Llewellyn who smartly diverted it past Barnsley's teenage goalkeeper Scott Flinders.
Suddenly a rather quiet affair had sprung spectacularly to life.
To their credit, Barnsley came back and in the 72nd minute a cracking 25-yard drive from Robbie Williams hit the underside of the bar and came out.
But moments later on-loan striker Michael Chopra equalised with his 17th goal of the season.
Barnsley had taken a 26th minute lead when another loan forward, Daniel Nardiello, had finished coolly after latching on to Chris Shuker's slide-rule through pass.