Mark Perrow reports from OakwellAaron Wilbraham struck a 79th minute equaliser to preserve City’s unbeaten start to their Sky Bet League One campaign.
All seemed to be going to plan for Steve Cotterill's side when Luke Ayling headed the visitors in front on 37 minutes, but hosts Barnsley were transformed after the break and levelled the scores through Sam Winnall before Conor Hourihane's penalty turned the game on its head.
It would take a 20-yard rocket from Wilbraham, completely out of character with his previous eight goals for the season, to keep City's invincible streak intact.
Both sides might have won it in a chaotic finale, but ultimately Cotterill would have to settle for a second successive 2-2 draw.
The manager welcomed Korey Smith back into his starting XI after a two-week absence through a hamstring injury, with the midfielder replacing Marlon Pack in the holding role.
City had scored inside the first 11 minutes in all of their last five league outings, but a repeat never looked on the cards besides a scuffed Joe Bryan shot from their first attack.
Instead it was the home team making much of the early running. Striker Winnall had Frank Fielding worried when his low drive from the edge of the box took a slight deflection and dribbled only inches wide, before Hourihane’s skewed cross required emergency action from the backpedalling City stopper.
Then Australian midfielder Ryan Williams surged into the penalty area, got himself in front of namesake Derrick and threw himself to ground – an easy one to give for the referee with the defender caught wrong side, but Darren Deadman remained unmoved by the Barnsley man’s theatrics.
Slowly but surely City began to find their usual rhythm. Tykes keeper Ross Turnbull, a Champions League winner in his time with Chelsea, was called into action to punch clear a dangerous Bryan cross, and should have been tested again on 28 minutes.
This time some intricate footwork from Luke Freeman down the right flank negotiated space for a cross swinging in towards the far post. As Bryan attacked it, Barnsley skipper Martin Cranie put him off just enough to ensure the Bristolian could only steer the ball wide from eight yards.
It was the best chance of the game to date at the end of City’s best spell, but the hosts soon reasserted themselves on a contest by now beginning to liven up.
Teenage striker Devante Cole, son of former City favourite Andy, forced Fielding into a parried save from a curling shot towards the top corner – a stop perhaps more routine than made to look by the number one.
Soon enough Fielding was expecting something similar from the on loan Manchester City youngster, who lined up another placed effort from the inside left position. When his shot ended up too close to the City keeper, the ball ran loose into the path of Winnall only for Williams to make an excellent sliding block.
It was a timely warning for the visitors, who responded in the best possible manner to take the lead eight minutes before the interval.
There was an air of controversy about the build-up when Ayling’s overhit pass was deemed to have taken a deflection off ex-City man Lewin Nyatanga, gifting the visitors an unexpected corner.
From Freeman’s deep delivery, Turnbull helped the ball on towards the far touchline where it was recycled to Bryan, whose cross was perfectly measured for Ayling
to head back across the Barnsley stopper and find the bottom corner.
It was a goal ensuring every City player wearing purple had scored at least once this season – a remarkable statistic before the end of October.
Cotterill’s side were showing visibly more confidence having taken the lead, but on the receiving end of a strong Barnsley response after half-time.
Cole was guilty of a bad miss when Joe Dudgeon’s left-wing cross looked tailor-made for an equaliser, only for the striker to head the ball back across Fielding from close range and offer Aden Flint the chance to make a crucial goal-line clearance.
But City did not heed the warning. Having survived a goalmouth scramble from a corner, the visitors were finally unlocked on the hour when another cross from the left dropped kindly for Winnall
, who swivelled and curled a delightful finish inside the far post.
The red-shirted siege was becoming relentless, with Freeman’s long ranger towards the top corner merely a temporary reprieve.
Barnsley’s Williams broke free down the left and pulled the ball back behind everybody, before the ball dropped to him again in space only for the midfielder to send his volley wide from 15 yards with time and space on his side.
City were under big pressure and succumbed midway through the second half when Hourihane
was needlessly pushed in the back by Ayling while running away from goal, albeit with minimal force, and duly picked himself up to slot a very confident spot-kick into the bottom corner past Fielding’s left hand.
From then on it was breathless viewing with City’s unbeaten start hanging by a thread.
Cotterill’s men responded in the only way they know and kept attacking, getting themselves back on level terms when Wilbraham
cracked a loose ball into the roof of the net from the edge of the box – comfortably the most spectacular of his nine goals for the season.
But far from settling for a point, the visitors kept coming. It proved almost to their own downfall but Hourihane wasted a golden chance on the counter-attack by being too selfish before striking the upright five minutes from time.
At the other end Wilbraham’s touch was heavy when put through by substitute Jay Emmanuel-Thomas, while Flint hung in the air in stoppage time and looked set to win it only for a brilliant piece of defending to preserve parity.