A 92nd-minute Giles Barnes goal denied league-leaders Cardiff three points.
Derby's late equaliser was wildly celebrated
Mike Chopra missed chances as Cardiff dominated a goalless first half, before Glenn Loovens put his side ahead with a strong header from Paul Parry's corner.
Steve Howard equalised, heading in Richard Jackson's right-wing cross, before Chopra looked to have won it.
The striker fired home Steve Thompson's centre right-footed from 12 yards, but Barnes connected with Jackson's cross for a spectacular 15-yard volley.
Loovens went off with a worrying looking cheek injury towards the end and was sent to hospital for a scan.
Former Bluebirds chairman Sam Hammam received a standing ovation before the kick-off at Ninian Park.
Cardiff manager Dave Jones:
"I don't think they were on the same park as us today. We could have been well out in front in the first half.
"I'm disappointed in drawing the game, but not in the way we played. It is a good point for us, because the two teams below us lost points.
"They came to do a job against us but we kept pulling them apart, so they changed it around, but we still continued to pull them apart.
"Some of the football we played was top quality, and the second goal we scored was out of this world."
Derby coach Julian Darby:
"I am over the moon for [Giles] Barnes, he's a young lad with a bit of everything. He's got bags of talent and does things like that every day in training.
"We knew the game was going to be tough and we needed that bit of luck. Cardiff deserve to be top of the league because they are a very good team.
"I did feel the longer the game went on, the more we looked like getting something from it.
"We would have taken a point before the game, but I think we've got nothing to fear from now on."
Cardiff: Alexander, McNaughton, Purse, Loovens (Johnson 62), Chambers, McPhail, Parry, Scimeca, Ledley, Thompson, Chopra.
Subs Not Used: Howard, Flood, Campbell, Kamara.
Goals: Loovens 52, Chopra 74.
Derby: Bywater, Edworthy, Camara, Leacock, Michael Johnson (Jackson 22), Oakley, Bisgaard (Barnes 72), Lupoli, Howard, Stead (Smith 80), Seth Johnson.
Subs Not Used: Grant, Bolder.
Goals: Howard 66, Barnes 90.
Ref: A Marriner (W Midlands).