Derby County's unbeaten run in Sky Bet League One came to an end at the hands of Peterborough United on New Year's Day.
A brace from James Collins looked to have won the game at one stage but two late goals from the visitors saw them snatch all three points.
In the most incredible of starts, the Rams found themselves in front within the opening 30 seconds.
Tom Barkhuizen got beyond his man down the right and whipped a lovely ball in for Collins who directed his header brilliantly into the bottom corner.
The Posh looked for an instant response of their own and nearly got one but Ephron Mason-Clark fired over from a promising position.
And they did find the equaliser in the opening 10 minutes. Harrison Burrows got in down the right and cut inside before firing an effort which beat Joe Wildsmith with the help of a deflection.
Mason-Clark then blazed over a good opportunity as the visitors found a new lease of life following the quick equaliser.
Ricky-Jade Jones was next to go close when he fired inches wide from the edge of the area.
Max Bird then went close up the other end as the game continued to be played at 100 miles per hour in the opening stages.
Collins had a good header well saved by Fynn Talley as he looked to almost mirror his goal from the opening 30 seconds.
Joe Wildsmith had to be at his best to deny the Posh taking the lead just before the break. Mason-Clark found Joel Randall on the edge of the area and the latter's effort was brilliantly tipped around the post for a corner by the Rams stopper.
Head Coach Paul Warne opted for a triple change at the break as he looked to turn the tide of the game in the second period.
But it was the visitors that missed a glorious opportunity to take the lead within the opening five minutes when Randall blazed over from six-yards out.
And it was Derby that were able to retake the lead on the hour mark and it was that man Collins again.
The Rams were given a penalty after a Posh defender had handled in the box. Collins stepped up and saw his penalty saved but the rebound fell kindly back to the striker who headed home in front of the south stand.
Substitute Callum Elder pulled off a miraculous block to deny Kwame Poku at the back post as the visitors came back in search of an equaliser.
And the visitors got an equaliser as the game entered the final 10 minutes and it was Poku with it. The winger rose highest to head into the far corner following a corner from the left.
Substitute Tyreece John-Jules nearly found a winner before time was up when he twisted and turned on the edge of the area before getting a shot away but his effort was really well saved by Talley.
And The Rams' unbeaten run would come to an end in the final minute of stoppage time. A corner wasn't dealt with by the defence and a kind deflection fell into the path of Jones who slid home the winner with seconds remaining.
Derby County: Wildsmith (GK), Wilson (72' Ward), Forsyth (46' Elder), Hourihane (C) (46' Sibley), Cashin, Barkhuizen (46' Thompson), Bird, Collins, Mendez-Laing (65' John-Jules), Nyambe, Nelson.
Substitutes: Vickers (GK), Bradley.
Peterborough United: Talley (GK), Burrows, Edwards, Knight, Mason-Clark, Poku, Randall (90' De Havilland), Jones, Kyprianou, Collins, Kioso (C) (76' Ajiboye).
Substitutes: West (GK), Katongo, Fernandez, Fuchs, Wakeling.
29,917 (1,665 Peterborough United supporters)
The Rams are back in Sky Bet League One action on Saturday and it's a lunchtime kick-off as they take on Fleetwood Town (12:30pm kick-off).
