Burnley were denied a first league victory since February as Mohammed Fuseini's dramatic stoppage-time equaliser earned Derby a 1-1 draw at Turf Moor in the Championship.
The Ghana winger, signed on loan from Belgian club Union Saint-Gilloise on transfer deadline day, drilled in an angled shot on the run, via the inside of the far post, for his first Derby goal.
Zeki Amdouni's 34th-minute far-post header looked to have given Burnley a much-needed victory to ease the pressure on their new head coach Nicky Hayen, already facing questions over his future despite only having taken charge in July.
Switzerland forward Amdouni bounced his far-post header into the net after goalkeeper Josh Vickers had flapped at a Lucas Pires corner.
But Fuseini's equaliser leaves Burnley winless and bottom of the Championship, having failed to gain three points from a match Hayen had described beforehand as "must-win".
Hayen had made six changes to try to revive a team beaten at Swansea last weekend - dropping goalkeeper Max Weiss and former Manchester City defender Kyle Walker, and bringing back winger Marcus Edwards, re-registered after being left out of Burnley's 25-man EFL squad at the start of the month.
Derby, themselves in the bottom three and with a long injury list, created the first two chances just after the quarter-hour mark. Midfielder David Ozoh's shot from outside the penalty area was deflected wide, and from the resulting corner delivered by Joe Ward, defender Dion Sanderson met the ball at the far post but could only head the ball back across goal.
Amdouni then headed Burnley in front with the game's first effort on target, but Derby could have drawn level three minutes before half-time. Former Blackburn forward Sammie Szmodics ran clear on to a long pass from Ward but was stopped as he collided with Gregoire Coudert.
With the goalkeeper down, Ryan Hedges' follow-up was blocked by Igor Julio, before Carlton Morris played the loose ball wide to Szmodics, whose shot from a tight angle was cleared from inside the six-yard box by Anel Ahmedhodzic.
Ozoh threatened an equaliser 50 seconds after half-time with a run down the left, which ended with a fierce angled shot that Coudert beat away at his near post, and Hedges then drove a good chance wide from 12 yards as Burnley failed to deal with a long throw.
Burnley, having ridden those scares, began to create pressure as they sought a second goal, and substitute Largie Ramazani was only denied by a fine Sanderson block after Jacob Bruun Larsen had exchanged passes with Pires to set him up.
Coudert made an excellent save low to his left to push away Bobby Clark's 20-yard drive inside the final quarter of an hour, but Derby drew level when Rhian Brewster sent fellow substitute Fuseini away to equalise.
Burnley's Nicky Hayen:
Asked if he expected to be in charge when Burnley return from the three-week international break for their next league match, away to Watford on October 10, Hayen said: "I don't know.
"I really hope so because I really work really hard for this club and I want to give back to the fans for their patience. I really understand how disappointed they are and that they even blame me. I don't have a problem with it."
Hayen had described the Derby game beforehand as "must-win" - against a team also in the relegation zone - but said he could not forecast the consequences of failing to claim victory.
"I don't know," he said. "You have to ask this question to other people, but I speak a lot with those people also.
"We always do like a recap of the game and have feedback and always have an honest conversation.
"So I don't know what's going to happen. I know the fans are disappointed. We have had a really bad start and this is also not what I expected.
"But I'm always resilient. I'm always a fighter. Tomorrow I come back with a new positive energy. That's always how I've worked. And that's the energy that I want to bring towards the players and towards this club."
Derby's John Eustace:
"We defended properly for the majority of the game, apart from the goal, which is another soft goal on our part, and limited Burnley to no opportunities, really.
"David Ozoh switched off for their goal. Part of his development is learning. Games are won and lost on set pieces, which everyone knows. And if we'd have lost today from that, it would have been a real kick in the teeth.
"It was a great finish from Mo for the equaliser.
"I'd obviously seen in his highlights reel that he likes to do a cartwheel when he scores and I said… He won't be doing it again. But when he scored, I asked him if he did his cartwheel, and he said yeah. So I hope there'll be a few more cartwheels to come."
