City succumbed to a first defeat in four matches as Rotherham United ran out 3-0 winners at New York Stadium.
City started firmly on the front foot but a hat-trick of chances came and went for the visitors before Jonson Clarke-Harris struck the first of a personal brace.
Kieran Agard was denied by Lee Camp when put clean through on goal before Clarke-Harris added his second from the penalty spot.
A 2-0 half-time deficit was hard on City, but Rotherham proved too tough a nut to crack and completed the scoring through captain Lee Frecklington 15 minutes from time.
Steve Cotterill named an unchanged team from the encouraging 1-1 draw with Hull City last time out, and saw his side start the game sharply as City created three chances inside the first four minutes.
Aden Flint stayed forward following the game’s first corner and met Jonathan Kodjia’s chipped cross with an acrobatic scissor kick that bounced safely into the arms of Camp.
Then Derrick Williams’ burst down the left flank took him all the way to the byeline where his low cross was met by Kodjia, whose shot flicked up off a defender on its way behind for another corner.
This time Luke Freeman took the kick short to Elliott Bennett, who was allowed to open up a shooting angle only to drag the chance wide of the near post.
But all of City’s good work would be undone by Clarke-Harris’ well-taken opener in the tenth minute.
Picking up possession near the right corner of the penalty area, the striker was allowed to step inside on to his stronger left foot and plant a curling shot just inside the far post from 20 yards.
Still City remained firmly on top. Bennett lashed a shot into the side-netting before Kodjia poked the ball through for Agard with only Camp to beat, but the keeper spread himself well to make a smart save.
Cotterill would have been irritated by the scoreline bearing in mind his team’s dominance, but he had Frank Fielding to thank for getting fingertips to an attempted cross from Clarke-Harris that was destined for the top corner – not that the officials saw the save, much to the disgust of the natives.
But Clarke-Harris would not have to wait long to add to his tally after Kodjia hauled down Kirk Broadfoot from an innocuous high ball into the box, paving the way for Rotherham’s top scorer to smash home the resulting spot-kick in the most uncompromising fashion imaginable.
Somehow City were 2-0 down and in need of inspiration. Freeman nearly provided it with a sharp turn to keep the ball in play before crossing with his right foot for Agard, whose glancing header dropped only inches beyond the far post.
The visitors’ frustrations were evident when Freeman went into the book for chopping down Clarke-Harris, but there was no reason to believe the game was out of reach when the half-time whistle sounded soon after.
Cotterill reshuffled his back three at the interval by introducing Liam Moore for Nathan Baker, whilst Agard would last only another 13 minutes before his first return to the New York Stadium was cut short by the arrival of Aaron Wilbraham in his place.
The former Rotherham striker, who played a key role in the Millers’ back-to-back promotions, would have traded the generous ovation that followed for another look at the chance saved by Camp at 1-0.
Cotterill was forced to replace the limping Kodjia midway through the second period as Simon Cox entered the fray at a time when City were enjoying no shortage of possession but struggling to penetrate a deep-lying defensive line.
Flint sneaked around the back to meet Marlon Pack’s floated free kick by hooking the ball back across goal and only just wide, but the damage would soon be broken beyond repair when Danny Ward’s cutback was dispatched by Frecklington for the killer third with 15 minutes left.