Daniel Powell produced a brilliant equaliser four minutes into added time to deny City a first home win of the season.
Jonathan Kodjia’s early goal looked to have secured an important victory against fellow promoted side MK Dons.
City spent the rest of the first half on the front foot but dropped deeper after the interval to make for a nervy climax, and substitute Powell struck with a curling shot to deflate the home support.
Bobby Reid returned to the starting line-up at the expense of Derrick Williams, while Joe Bryan reverted to his orthodox left wing-back position with Korey Smith still sidelined by a groin injury.
Reid may have felt hard done by to be overlooked in Smith’s absence at Ipswich Town last time out, but took little time to make an impression on home soil as he laid the opening goal on a plate for Kodjia.
It was the tenacity of Reid that forced a defensive mix-up between centre-backs Kyle McFadzean and Antony Kay, seizing on a loose touch from the latter before his pace took him clear of the desperately retreating pair.
Had the roles been reversed, you suspect Kodjia would have gone for goal, but the young Bristolian showed his maturity in turning a seemingly straightforward chance into an unmissable one for his team-mate, taking City’s top scorer up to six for the season.
It was the first time the hosts had scored first in a game since their only victory to date at Middlesbrough in August.
Reid tried his luck from range five minutes later with a shot that did not trouble goalkeeper David Martin but did demonstrate his obvious confidence.
City were not peppering Martin’s goal but still had a stranglehold on the game and McFadzean’s frustration was clear to see when he cynically blocked off Kodjia, before evergreen left-back Dean Lewington was booked for obstructing Mark Little.
For a team renowned for their easy-on-the-eye football, MK were showing a far less attractive side to their game, as Jake Forster-Caskey was next to be carded after clattering into Reid, who had frankly made the England Under-21 international look distinctly average.
Still chances were at a premium, with Frank Fielding no more than a spectator, but opposite number Martin must have feared the worst when Kodjia skipped past McFadzean and eventually teed up Luke Freeman, who lashed the bouncing ball over the crossbar from 14 yards.
Kodjia would cause the same problem from the same run when McFadzean was again guilty of misjudging an interception, as the Frenchman raced into the box but this time ignored Freeman and Aaron Wilbraham to his right, instead stinging the palms of Martin with a shot admittedly too close to the keeper.
Reid had been City’s best player and was involved again at the start of the second half when Martin dived at his feet to tip the ball away for a corner. Had he mistimed it, a penalty would surely have followed.
But the Dons could only improve and eventually found their feet ten minutes into the second half.
Reid was guilty of overplaying on the edge of the box and had his pocket picked by Forster-Caskey, whose well-disguised backheel set up Ben Reeves to let fly with a shot spectacularly helped on its way by Fielding.
There was another scare just after the hour when Lewington delivered into a dangerous area seeking the near post run of Simon Church, who failed to get a touch but turned to watch the ball run into Fielding’s left-hand post.
In the end Church was flagged offside, but whether the goal would have stood had the ball found the net is up for debate.
Dons boss Karl Robinson made a double change on 69 minutes as his team began to take increasing control of a game they took an eternity to get into.
Nicky Maynard took the place of Church to prompt a chorus of boos, while fellow replacement Rob Hall threatened to make an immediate impact with a fizzing low drive that forced Fielding into a sharp stop.
McFadzean soon tried his luck from distance with a sweetly-struck effort that veered inches wide as the home crowd started to get agitated.
Hall was looking lively, and he fired a low ball across the six-yard box that begged for a touch only for the sliding Forster-Caskey to be inches short of providing it.
The winger repeated the trick two minutes from time only to be infuriated by a lack of goalscoring instinct from any of his team-mates, before Powell rescued a point at the death.
There was still time for Little to embark on a lung-busting run to the byeline and cross for Kodjia, whose shot straight at Martin was the final act on a frustrating afternoon.