Doncaster snatched a stoppage-time leveller to earn a 1-1 draw at Peterborough.
Ben Whiteman slotted his seventh goal of the season from close range in the 93rd minute after a blocked shot fell perfectly into his path.
It provided a dramatic conclusion to Rovers boss Darren Ferguson's return to Posh - a club he guided to three promotions during two spells as manager.
His current side looked set for defeat after falling behind to a 14th minute goal from Danny Lloyd. The United man struck for the 10th time this season after Ryan Tafazolli headed down a Marcus Maddison free-kick.
Only a smart save from Ian Lawlor prevented Lloyd from doubling the advantage, before the post came to Rovers' rescue in the second half when Lawlor was beaten by a Chris Forrester thunderbolt from 25 yards.
But Rovers piled on the pressure late on. Whiteman was denied by Jonathan Bond before Alfie May fluffed a glorious headed opportunity, but Whiteman made the most of his second chance to ensure the spoils were shared.