Paul Dickov broke Manchester City's heart on his return to his former club by scoring a late equaliser for bottom club Blackburn Rovers.
City had looked set to register victory through Antoine Sibierski's first league goal of the season until Dickov's late intervention.
Dickov burst through on goal only to be brought down by Danny Mills who was sent off as the Scottish striker had been in a goalscoring position.
And Dickov jumped to his feet to convert the 78th minute spot kick, his fourth goal of the season.
It left City frustrated as the euphoria of the Derby draw at Old Trafford evaporated as they left the field to a chorus of boos and jeers.
Sibierski had looked to be the winner in what was a dire Premiership fixture.
While the French striker claimed his goal, manager Kevin Keegan also deserved credit.
It was Keegan's tactical switch late in the opening half which was rewarded with a memorable move which brought about the goal.
The City chief moved Shaun Wright-Phillips from a central striking spot to his usual position on the right wing, with Sibierski switching inside to partner Nicolas Anelka.
Wright-Philips provided the low cross from the right for Sibierski to score with a simple side foot from inside the six-yard box.
Keegan, unsurprisingly, fielded an unchanged side following their gritty derby draw at Manchester United last Sunday.
Blackburn's one alteration from their 1-1 draw at Norwich last Saturday saw John Stead replace the suspended Jay Bothroyd.
In a largely disappointing period, City rarely threatened Rovers keeper Brad Friedel.
Until Sibierski struck late in the half, the American only had two serious shots to deal with and each time he comfortably dealt with strikes at goals from Anelka.
The first was a drive which Friedel saved diving low to his right and that was followed by a fiercely struck free kick which he sifted to safety.
Blackburn gave a spirited account of themselves with Jonathan Stead having a couple of decent strikes at goal.
City finally made the breakthrough in the 44th minute with a delightfully works move involving Steve McManaman and Wright-Phillips who set up Sibierski who netted his third goal of the season.
Blackburn manager Mark Hughes made a half-time substitution bringing on Matt Jansen in place of Stead to try and provide more forward punch.
But City remained the more dangerous attacking side and Mills almost doubled their lead with a terrific drive which Friedel could only parry.
City brought on Claudio Reyna, returning after a two-month injury lay-off, midway through the second half to strengthen their midfield.
City were never in any danger until Blackburn were handed an unexpected lifeline when Dickov won them their point-saving penalty.
And to compound City's misery, Mills was sent off with the right-back suspended for next Saturday's league match at Portsmouth.
If any side was going to conjure a winner in the dying minutes it was going to be Blackburn.
City keeper David James had to acrobatically tip over a deflected cross from Brett Emerton whilst substitute David Thompson forced the City keeper to make another decent save to keep out his drive.
And in stoppage time the ever dangerous Dickov may also have added insult to injury by scoring a winner, but his rasping drive narrowly cleared the crossbar.
Man of the Match: Paul Dickov - The ever-busy frontman came back to hanut one of his former clubs and earn Rovers a crucial share of the spoils.