Barnsley's Cauley Woodrow struck in the 94th-minute to deny Bristol City all three points in a toughly contested battle at Oakwell.
Managerless Barnsley, under the guidance of caretaker manager Adam Murray fought back from two goals down to claim a hard-fought point against an in-form City side.
Headers from Bristol City's Ashley Williams and Andreas Weimann in each half looked to set Bristol City up for a memorable victory, but a Aapo Halme header and a last-gasp Woodrow strike from close-range helped the hosts clinch a well-earned point.
In the opening exchanges, both sides created some inviting opportunities, with Dimitri Cavaré and Halme coming close with headed efforts, whilst Bristol City's Callum O'Dowda tested Brad Collins with a low-driven effort.
Daniel Bentley kept Bristol City in the game with two stunning first-half saves, denying Mallik Wilks and Conor Chaplin. Right on the stroke of half-time and completely against the run of play, City took the the lead as Williams headed the ball home from close-range to send his side into the lead at the break.
In an evenly-contested start to the second-half, the visitors doubled their lead as Weimann flicked home Niclas Eliasson's corner, just 19 minutes from time.
Just six minutes later, Barnsley responded as Halme headed home a powerful effort to reduce the deficit with just 13 minutes to spare.
Late drama
As Barnsley poured bodies forward in the closing phases of the game, they were rewarded for their perseverance as Woodrow bundled the ball home from close-range after Elliot Simoes' cross was diverted towards goal by Patrick Schmidt.
Barnsley: Collins, Diaby, Halme, Sibbick, Cavaré, Dougall, Mowatt (c), Brown (Simoes, 81'), Chaplin (Schmidt, 73'), Woodrow, Wilks (Thomas, 58').
Bristol City: Bentley, Brownhill (c) (Eliasson, 30'), O'Dowda, Weimann, Watkins (Semenyo, 72'), Kalas, Moore (Baker, 72'), Rowe, Williams, Pereira, Massengo.
Post-match reaction
After scoring a last-gasp equaliser for his side, Cauley Woodrow told Sky Sports: "We conceded two poor goals from set pieces, I missed a chance just before the end, and I thought that was it. But, we kept going to the end and thankfully I was able to get on the end of it and it went in.
"We're fighting for our lives down here and they're obviously pushing for promotion so it was always going to be a tough game and we believed that if we stuck at it and kept fighting then we had a chance.
"We're disappointed not to get a win and we need wins, but a point's not a bad result after going 2-0 down."
After a heroic fightback from his side, Barnsley caretaker manager, Adam Murray shared his thoughts on his young side's efforts, losing just once during his four games in charge: "I prayed the goal was coming," said Murray to Sky Sports
Perseverance
"I think the bodies we put put forward and the pressure we put on in the last 15 minutes, you're always hoping that one's going to fall in. I think that a couple of ricochets tonight didn't go our way and I think that's probably been the story of our season that we've not quite had the rub of the green and that little bit of luck at times where we've needed it. But, maybe we've got a little bit at the end there."
On the 'poor' marking for the first goal especially, Murray admits that his team must do better.
"This is the frustrating part, the work we do on the training ground is based around things like that and it's for young players that we've got and the lesson's we're learning. We're in the Championship, we can't afford to be disorganised. We've got to do better, the boys know that."
The Bristol City boss insists that his side had just 45 seconds to close out the win, and they paid a hefty price for it.
Frustration
"We've got 45 seconds to see the game out," said Johnson. "It was a difficult game, difficult conditions, it wasn't one for the football purists, if you like, but it was a battle and I felt that we should've been much more in control, particularly when going 2-0 up.
"Individuals have got to do their jobs, and if we're serious about being successful, then that element of it is really important. We're a very young side, we are patching up a little bit in terms of positioning at the moment, but there's no excuse for tonight, and I'm very disappointed with some of the performances in the last 15-20 minutes."
Johnson added: "The lads want to win, they're absolutely devastated. We've come away with a point away to Barnsley but from a very comfortable winning position. We had ambitions to go joint-top tonight and we fall short in the last 45 seconds of a football match, so you can understand the frustration."