Chris Martin's late penalty earned promotion-chasing Derby a draw against unbeaten Championship leaders Brighton.
James Wilson flicked home his second goal in two starts to put the visitors ahead against the run of play, but Bradley Johnson's far-post header levelled matters by half-time.
Rajiv van La Parra's strike, after a swift counter-attack, looked to have secured victory for the Seagulls.
But Martin made it 2-2 after Gordon Greer fouled Johnny Russell.
Martin's coolly taken spot-kick denied Brighton a win, but they remain unbeaten in 20 league games this season and stay two points clear at the top of the table after Middlesbrough's goalless draw away at Birmingham City.
The fine run looked in doubt early on as Derby, who drop a place to fourth, could have been ahead inside a minute through a Tom Ince strike that was deflected wide.
It set the tone for a bright start by the hosts with Martin having a shot saved, and Jason Shackell seeing a header cleared off the line before Ince volleyed straight at goalkeeper David Stockdale.
Brighton were lively on the break and went in front when on-loan Manchester United striker Wilson slotted the ball in from Jamie Murphy's fine cross following good work by Inigo Calderon.
Derby, who themselves have only lost twice in the league, slowly recovered and Johnson's towering header from Jacob Butterfield's deep corner deservedly brought them level.
Both sides struggled to create clear chances after the interval, but Brighton's quality on the break was apparent again when Dutch substitute Van La Parra sent the ball past keeper Lee Grant after Johnson was dispossessed in midfield.
Martin almost levelled after a sloppy backpass before scoring his first goal in seven games when his 87th-minute penalty beat Stockdale.
Derby boss Paul Clement:
"We didn't deserve to lose the game, our start was very positive and then they produced a real moment of quality with a well taken goal against the run of play.
"A lot of credit goes to our players for not giving up, to keep going, and it was a cool finish from Chris (Martin) under real pressure. They had a difficult game to today and our players afterwards felt like it was a loss.
"We have a good record at home and that's the standards we are working towards but overall it's a hard fought point and I would have been really disappointed if we had lost that game."
Brighton boss Chris Hughton:
(On the late penalty) "I thought it was very harsh. Unless somebody shows me a different angle, from the one I've seen there's no doubt Gordon dives in because he has to but I don't see contact.
"The win would have meant a lot to us and we are disappointed but I think you have to give our players credit to come here against a team on such a good run with the quality they've got and I don't think anyone would have begrudged us the win."
Full Time Match ends, Derby County 2, Brighton and Hove Albion 2.
90:00 +5:07 Full timeFull Time Second Half ends, Derby County 2, Brighton and Hove Albion 2.
90:00 +3:29Richard Keogh (Derby County) wins a free kick in the defensive half.
90:00 +3:29Foul by Lewis Dunk (Brighton and Hove Albion).
90:00 +2:56Corner, Brighton and Hove Albion. Conceded by Jason Shackell.
90:00 +1:11Foul by Tom Ince (Derby County).
90:00 +1:11Lewis Dunk (Brighton and Hove Albion) wins a free kick in the defensive half.
89:34Hand ball by Bobby Zamora (Brighton and Hove Albion).
89:00Foul by Cyrus Christie (Derby County).
89:00Jamie Murphy (Brighton and Hove Albion) wins a free kick in the defensive half.
87:25 Goal scoredGoal! Goal! Derby County 2, Brighton and Hove Albion 2. Chris Martin (Derby County) converts the penalty with a right footed shot to the bottom left corner.
86:14Penalty Derby County. Johnny Russell draws a foul in the penalty area.
86:14Penalty conceded by Gordon Greer (Brighton and Hove Albion) after a foul in the penalty area.
86:02Attempt missed. Jason Shackell (Derby County) header from the centre of the box is close, but misses to the left. Assisted by Johnny Russell with a cross following a corner.
85:49Corner, Derby County. Conceded by David Stockdale.
85:34Attempt blocked. Tom Ince (Derby County) left footed shot from outside the box is blocked. Assisted by Chris Martin.
81:59 SubstitutionSubstitution Substitution, Brighton and Hove Albion. Rohan Ince replaces Tomer Hemed.
81:31 SubstitutionSubstitution Substitution, Brighton and Hove Albion. Bobby Zamora replaces James Wilson.
80:46Corner, Derby County. Conceded by David Stockdale.
80:45Attempt saved. Johnny Russell (Derby County) left footed shot from the left side of the box is saved in the top right corner. Assisted by Chris Martin.
Substitution Substitution, Derby County. Darren Bent replaces George Thorne.
76:17Corner, Derby County. Conceded by Bruno.
74:40 Goal scoredGoal! Goal! Derby County 1, Brighton and Hove Albion 2. Rajiv van La Parra (Brighton and Hove Albion) right footed shot from the right side of the box to the top right corner. Assisted by Dale Stephens.
73:16 SubstitutionSubstitution Substitution, Derby County. Jeff Hendrick replaces Jacob Butterfield.
71:52Attempt blocked. Tomer Hemed (Brighton and Hove Albion) right footed shot from the centre of the box is blocked. Assisted by James Wilson with a headed pass.
71:25Foul by Cyrus Christie (Derby County).
71:25Jamie Murphy (Brighton and Hove Albion) wins a free kick in the attacking half.
69:23Delay over. They are ready to continue.
67:44Delay in match Cyrus Christie (Derby County) because of an injury.
65:38Offside, Brighton and Hove Albion. Lewis Dunk tries a through ball, but Tomer Hemed is caught offside.
62:39 SubstitutionSubstitution Substitution, Derby County. Johnny Russell replaces Andreas Weimann.
57:26Attempt blocked. Tom Ince (Derby County) left footed shot from outside the box is blocked.
56:36Chris Martin (Derby County) wins a free kick in the attacking half.
56:36Foul by Beram Kayal (Brighton and Hove Albion).
56:01Chris Martin (Derby County) wins a free kick in the attacking half.
56:01Foul by Gordon Greer (Brighton and Hove Albion).
52:49Corner, Brighton and Hove Albion. Conceded by Lee Grant.
51:41Attempt missed. Tom Ince (Derby County) left footed shot from the centre of the box misses to the left. Assisted by Jacob Butterfield.
46:57Attempt missed. Tom Ince (Derby County) left footed shot from the centre of the box is close, but misses to the left. Assisted by Chris Martin.
46:03Richard Keogh (Derby County) wins a free kick in the defensive half.
46:03Foul by Lewis Dunk (Brighton and Hove Albion).
45:41Corner, Brighton and Hove Albion. Conceded by Jason Shackell.
45:36Attempt blocked. Rajiv van La Parra (Brighton and Hove Albion) left footed shot from the right side of the box is blocked. Assisted by Bruno.
45:00Second Half begins Derby County 1, Brighton and Hove Albion 1.
45:00 +4:05 Half timeHalf Time First Half ends, Derby County 1, Brighton and Hove Albion 1.
45:00 +2:38Attempt missed. James Wilson (Brighton and Hove Albion) left footed shot from the right side of the box misses to the left. Assisted by Tomer Hemed.
44:54Attempt missed. Bradley Johnson (Derby County) right footed shot from the centre of the box misses to the right. Assisted by Chris Martin.
43:38Attempt missed. Andreas Weimann (Derby County) left footed shot from the centre of the box misses to the right. Assisted by Tom Ince.
43:37Attempt missed. Tom Ince (Derby County) right footed shot from outside the box is close, but misses to the left. Assisted by George Thorne.
42:19Foul by Stephen Warnock (Derby County).
42:19Rajiv van La Parra (Brighton and Hove Albion) wins a free kick in the defensive half.
40:28 Goal scoredGoal! Goal! Derby County 1, Brighton and Hove Albion 1. Bradley Johnson (Derby County) header from very close range to the high centre of the goal. Assisted by Jacob Butterfield with a cross following a corner.
40:00Corner, Derby County. Conceded by Lewis Dunk.
36:42Attempt missed. Bradley Johnson (Derby County) header from very close range is too high. Assisted by Tom Ince with a cross following a corner.
36:14Corner, Derby County. Conceded by Lewis Dunk.
36:05Attempt saved. Bradley Johnson (Derby County) left footed shot from outside the box is saved in the top right corner. Assisted by George Thorne.
32:59Attempt missed. Bradley Johnson (Derby County) left footed shot from outside the box misses to the right.
31:06 BookingBooking Tomer Hemed (Brighton and Hove Albion) is shown the yellow card for a bad foul.
31:02George Thorne (Derby County) wins a free kick in the attacking half.
31:02Foul by Tomer Hemed (Brighton and Hove Albion).
30:17Chris Martin (Derby County) wins a free kick in the attacking half.
30:17Foul by Dale Stephens (Brighton and Hove Albion).
29:31Foul by Andreas Weimann (Derby County).
29:31James Wilson (Brighton and Hove Albion) wins a free kick on the right wing.
29:03Bradley Johnson (Derby County) wins a free kick in the defensive half.
29:03Foul by James Wilson (Brighton and Hove Albion).
28:16 BookingBooking Bradley Johnson (Derby County) is shown the yellow card for a bad foul.
28:14Foul by Bradley Johnson (Derby County).
28:14Dale Stephens (Brighton and Hove Albion) wins a free kick in the defensive half.
27:33Attempt saved. Jamie Murphy (Brighton and Hove Albion) right footed shot from outside the box is saved in the bottom right corner.
26:56 SubstitutionSubstitution Substitution, Brighton and Hove Albion. Rajiv van La Parra replaces Solly March because of an injury.
26:39Delay over. They are ready to continue.
24:35Delay in match Solly March (Brighton and Hove Albion) because of an injury.
23:50Richard Keogh (Derby County) wins a free kick in the defensive half.
23:50Foul by Tomer Hemed (Brighton and Hove Albion).
22:51Hand ball by Andreas Weimann (Derby County).
21:19 Goal scoredGoal! Goal! Derby County 0, Brighton and Hove Albion 1. James Wilson (Brighton and Hove Albion) left footed shot from very close range to the top right corner. Assisted by Jamie Murphy with a cross.
18:18Foul by George Thorne (Derby County).
18:18Jamie Murphy (Brighton and Hove Albion) wins a free kick in the attacking half.
17:03Delay over. They are ready to continue.
15:24Delay in match Íñigo Calderón (Brighton and Hove Albion) because of an injury.
12:19Attempt saved. Tom Ince (Derby County) left footed shot from outside the box is saved in the top centre of the goal. Assisted by George Thorne with a headed pass.
11:50Corner, Derby County. Conceded by Tomer Hemed.
11:49Attempt blocked. Jason Shackell (Derby County) header from the centre of the box is blocked. Assisted by Jacob Butterfield.
11:14Delay over. They are ready to continue.
10:15Delay in match Solly March (Brighton and Hove Albion) because of an injury.
9:41Chris Martin (Derby County) wins a free kick in the attacking half.
9:41Foul by Bruno (Brighton and Hove Albion).
8:32Corner, Brighton and Hove Albion. Conceded by Richard Keogh.
8:30Attempt blocked. Tomer Hemed (Brighton and Hove Albion) right footed shot from outside the box is blocked. Assisted by Solly March.
7:55Attempt missed. Bradley Johnson (Derby County) left footed shot from outside the box is high and wide to the left.
5:21Foul by Stephen Warnock (Derby County).
5:21Solly March (Brighton and Hove Albion) wins a free kick in the defensive half.
4:21Attempt saved. Chris Martin (Derby County) left footed shot from the centre of the box is saved in the top left corner.
2:15Attempt missed. Solly March (Brighton and Hove Albion) left footed shot from the right side of the box misses to the right. Assisted by Tomer Hemed.
0:25Corner, Derby County. Conceded by Dale Stephens.
0:23Attempt blocked. Tom Ince (Derby County) left footed shot from the centre of the box is blocked. Assisted by Chris Martin.
0:00First Half begins.
0:00Lineups are announced and players are warming up.
Live data and text provided by our data suppliers