David McGoldrick and Nathaniel Mendez-Laing both struck inside three minutes to complete a stunning late comeback win for Derby at Port Vale that extended the Rams' unbeaten Sky Bet League One run to 14 matches.
The hosts were poised for victory after Funso Ojo marked his first start since September by converting on the rebound following Joe Wildsmith's save from Dan Butterworth's initial attempt.
Derby appeared to be running out of ideas - and low on good fortune - when manager Paul Warne sent on Lewis Dobbin after 68 minutes.
Forward Dobbin, on loan from Everton, had one effort repelled by Jack Stevens - who earlier saved point-blank from McGoldrick - before turning provider in dramatic fashion.
The 20-year-old scorched down the left in the 87th minute to cross for McGoldrick to touch home his ninth goal of the campaign.
And Dobbin created a sense of deja vu two minutes later, escaping on the same flank to steer a ball to the near post where Mendez-Laing arrived to rifle into the roof of the net and spark jubilant scenes among the 3,821 travelling fans.
There was still time for Dan Jones to head narrowly wide in search of an equaliser, while Dobbin nearly capped his blistering cameo in fine style but sent a curling strike against the bar.
Derby stay fourth after claiming a fifth straight victory but close within eight points of Sheffield Wednesday in second. Port Vale slip one position to 14th.