Former Scunthorpe United defender Shelton Martis struck with just three minutes to go, as Doncaster Rovers snatched a 4-3 victory over their local rivals in the Championship.
The Iron led once and twice came from behind, but, as it has done all season, their defensive frailties came back to haunt them at the Keepmoat Stadium.
They were sent an early warning as James Coppinger struck the post with a curling effort, but Scunthorpe responded. It was then winger Martyn Woolford's turn to be denied by the framework.
Martis was denied by a terrific save from Joe Murphy. Moments later, the Iron went ahead when Paul Hayes played in Gary Hooper to score his 19th goal of the campaign.
The lead was short-lived.
David Mirfin's error allowed Jay Emmanuel-Thomas to lob Murphy for the equaliser.
Murphy had to be alert to prevent Emmanuel-Thomas from notching his second, but Rovers did finally get ahead before half-time when Jordan Mutch slotted home.
Martis' slip allowed Hayes to fire Scunthorpe level after the restart, but it did not take long for Doncaster to restore their lead. James Hayter netted with a shot that went in off the inside of the post.
Garry Thompson dragged a glorious chance wide, and ex-Rover Jonathan Forte rattled the underside of the bar as the Iron pressed for an equaliser. It came eventually, when Hooper stabbed in after a goalmouth scramble.
But Rovers were not done.
Paul Heffernan brought a fingertip-save out of Murphy. On the resulting corner Martis, who had a loan spell with Scunthorpe two years ago, headed home to steal the points for Doncaster.