Aaron Wilbraham’s 71st minute goal was not enough to strengthen City’s hold on top spot as the Sky Bet League One leaders were pegged back by a quick-fire equaliser in Oldham.
Goal number 18 of the striker’s season seemingly had City on their way to a hard-fought away win on an awful pitch in Greater Manchester, but Carl Winchester’s low shot bounced awkwardly beyond the reach of Frank Fielding to even things up four minutes later.
The City goalkeeper was the busier of the two in the closing stages, saving from both Conor Wilkinson and Jonathan Forte to earn a share of the spoils.
Steve Cotterill named an unchanged team following the 2-2 draw with Barnsley last time out at Ashton Gate.
It was City who enjoyed the first sight of goal, when Luke Freeman was afforded too much time on the edge of the box, but the midfielder dragged a low shot two yards wide.
But Oldham would not take long to come into the game, starting with a pacey front three keen to stretch the league leaders at every opportunity.
Boundary Park old boy Korey Smith would have to take matters into his own hands as early as the ninth minute, going into the book after clearly obstructing the run of top scorer Forte.
But Smith was soon on the attack, crossing for Wilbraham to rise highest at the far post and send a downward header bouncing just beyond the opposite upright.
It had been an entertaining start to the game. City would come again a minute later, as Freeman jinked his way to the byeline and stood up an enticing cross for Joe Bryan to attack, this time forcing a save from Joel Coleman in the Oldham goal.
Then a quick break from their own box set Bryan free down the left. His lofted pass infield was perfectly judged to pick out Freeman, whose first touch was good before he snatched at the shot with the ball running away from goal.
Freeman was off target with another strike from distance after Oldham enjoyed their best spell of the half.
First Winchester’s goalbound shot was helped over his own crossbar by Derrick Williams, before Fielding allowed a dipping effort from Mike Jones to escape from his grasp after it took an awkward bounce in front of the City number one.
There was a good tempo about the contest, although there were times when both teams would have been happy to slow things down only to struggle to sustain any prolonged possession.
A bobbly pitch, including a particularly muddy strip down the City right, contrived to halt both sides in their tracks and curtail the early flow of chances.
It was a pattern that continued into the second half. Suddenly opportunities were few and far between before Cotterill reacted by introducing Jay Emmanuel-Thomas for Kieran Agard, who had worked tirelessly without reward for the first hour.
Instead it was Oldham threatening to open the scoring soon after the change was made, as defender Connor Brown was invited to try his luck from distance – a skidding shot kept out by Fielding, who was back to his feet quickly to keep out Dominic Poleon on the rebound, only for the onrushing striker to be flagged offside.
Captain Wade Elliott followed Emmanuel-Thomas in arriving from the bench, replacing Marlon Pack as City searched for more control in an increasingly scrappy affair.
Within five minutes Elliott was involved as the visitors struck a crucial opener.
The Oldham fans were on their feet when Coleman’s quick distribution set the lightning quick Forte sprinting away down the left.
Thankfully for City, Luke Ayling was quick to read the danger and step across, in turn setting up a swift counter-attack.
Elliott received the ball in the centre circle and turned to his left to find Bryan, who found Freeman rushing towards the byeline.
When his cutback met the near-post run of Wilbraham, there was only ever going to be one result as the striker gobbled up the chance from six yards.
But any hopes of City being home and hosed lasted no longer than four minutes, as a speculative Winchester drive deceived Fielding with an ugly bounce just in front of his dive to nestle in the far corner of the net.
Suddenly the wind was well and truly in the sails of the home side and Fielding was soon called upon to keep the scores level, spectacularly tipping the ball away from goal after Wilkinson hooked it more in hope than expectation towards the top corner.
A game that had descended into an extended lull had its spark back. The momentum was with Oldham but City were not prepared to settle for a point, as one Bryan cross fizzed agonisingly beyond the reach of both Wilbraham at the near post and Elliott at the far.
Cotterill threw his last card by opting for George Saville to replace the injured Mark Little as City reverted to a midfield diamond in the closing stages.
Six added minutes were signalled to trigger a late siege on the Oldham penalty area, but the hosts stood firm and Saville’s right-footed shot high and wide of goal was the closest City came to a dramatic winner.