El-Hadji Diouf's second-half penalty secured a point for Doncaster in their fight to avoid relegation and kept Brighton out of the play-off zone.
Diouf stepped up to score coolly from the spot with 10 minutes left after Adam El-Abd was penalised for handball.
Brighton had led at the interval after Craig Mackail-Smith poked home his 11th of the season from close range.
The Seagulls remain a point outside the top six, while Rovers stay bottom, five points from safety.
Blustery conditions and a ragged playing surface made for a scrappy opening, during which home captain Brian Stock hobbled from the field to be replaced by Simon Gillett.
Matters were made worse for Stock's team-mates in the 20th minute when Liam Bridcutt's heavily scuffed effort fell into the path of Mackail-Smith, who managed to prod past Carl Ikeme at the second attempt.
Mamadou Bagayoko almost levelled soon after but his audacious backheel was saved by Peter Brezovan.
The home side missed a further chance to equalise when James Hayter blazed over from inside the area after Gillett's shot was blocked.
Doncaster remained on top at the start of the second period and James Coppinger volleyed narrowly wide before full-back Tommy Spur sent a drilled effort close.
The Seagulls were reduced to breakaway chances, Mackail-Smith failing to get his head to a dangerous centre from substitute Craig Noone.
And just as the home side's efforts began to take on an air of desperation, they were handed a lifeline when El-Abd inexplicably handled a Diouf corner, allowing the Senegal international to slot home from the spot.
Brighton manager Gus Poyet:
"We didn't play well but it was difficult to pass the ball on such a bumpy pitch.
"I'm not making that an excuse because it was the same for both teams and I feel sorry for the Doncaster players because we can go home now while they have to play on it every other week.
"I felt sorry for the fans as well because it was an ugly game - there were some bad decisions for both sides and it wasn't pretty to watch."
Doncaster manager Dean Saunders:
"They had one attack and scored in the first half and it was a terrible goal to concede from our point of view.
"But the lads showed a brilliant attitude to fight back and I thought we were the better team overall.
"I agree the pitch is not good but I thought we played great on it today.
"We may be bottom but we are still in there fighting with games in hand -but we need to score more goals."
Full Time The final whistle is blown by the referee.
Kyle Bennett fouled by Alan Navarro, the ref awards a free kick. Direct free kick taken by Carl Ikeme, Fabien Robert produces a right-footed shot from close range that goes over the bar.
Habib Beye fouled by Sam Vokes, the ref awards a free kick. Direct free kick taken by Habib Beye.
Corner taken left-footed by Craig Noone.
Adam El-Abd restarts play with the free kick. Inswinging corner taken by El-Hadji Diouf, Adam El-Abd manages to make a clearance. Outswinging corner taken by Tommy Spurr from the right by-line played to the near post.
Booking Habib Bamogo receives a caution.
Free kick awarded for a foul by Craig Noone on Pascal Chimbonda. Carl Ikeme restarts play with the free kick. Habib Bamogo concedes a free kick for a foul on Gordon Greer.
Substitution Craig Mackail-Smith leaves the field to be replaced by Sam Vokes.
Substitution Will Buckley goes off and Gai Assulin comes on.
Pascal Chimbonda challenges Craig Noone unfairly and gives away a free kick. Free kick taken by Liam Bridcutt.
Will Buckley takes a shot. Save by Carl Ikeme.
78:31 Goal scored
Goal! - El-Hadji Diouf - Doncaster 1 - 1 Brighton El-Hadji Diouf scores a power penalty. Doncaster 1-1 Brighton.
Short corner taken by El-Hadji Diouf.
Direct free kick taken by Will Buckley.
Booking Pascal Chimbonda goes into the referee's book.
Foul by Pascal Chimbonda on Craig Noone, free kick awarded.
Substitution Kyle Bennett is brought on as a substitute for James Hayter.
Booking Caution for Habib Beye.
Habib Beye concedes a free kick for a foul on Craig Mackail-Smith. Adam El-Abd takes the direct free kick.
Unfair challenge on Giles Barnes by Will Buckley results in a free kick. Shelton Martis restarts play with the free kick.
Shot from deep inside the area by Joe Mattock clears the crossbar.
Substitution James Coppinger leaves the field to be replaced by Fabien Robert.
Simon Gillett gives away a free kick for an unfair challenge on Ashley Barnes. Free kick taken by Gordon Greer.
Corner taken by Will Buckley from the right by-line, Carl Ikeme manages to make a clearance.
Booking Gonzalo Jara Reyes is cautioned.
Free kick awarded for a foul by Adam El-Abd on El-Hadji Diouf. Giles Barnes takes the free kick. Corner taken by El-Hadji Diouf.
Substitution Craig Noone on for Abdul Razak.
Liam Bridcutt challenges Giles Barnes unfairly and gives away a free kick. Shelton Martis takes the free kick.
Alan Navarro challenges El-Hadji Diouf unfairly and gives away a free kick. Free kick taken by El-Hadji Diouf.
El-Hadji Diouf takes a inswinging corner.
Shot by James Coppinger from deep inside the penalty area misses to the left of the target.
Inswinging corner taken by El-Hadji Diouf, clearance by Will Buckley.
The second half begins.
45:00 +3:20 Half time
Half Time The referee calls an end to the first half.
Craig Mackail-Smith fouled by Shelton Martis, the ref awards a free kick. Direct free kick taken by Liam Bridcutt.
Effort on goal by James Hayter from inside the penalty area goes harmlessly over the bar.
Short corner taken by Will Buckley from the left by-line, clearance by James Hayter.
Shelton Martis gives away a free kick for an unfair challenge on Craig Mackail-Smith. Liam Bridcutt restarts play with the free kick.
Habib Beye challenges Craig Mackail-Smith unfairly and gives away a free kick. Direct free kick taken by Joe Mattock.
Joe Mattock concedes a free kick for a foul on James Chambers. El-Hadji Diouf restarts play with the free kick.
Will Buckley takes the inswinging corner, clearance made by El-Hadji Diouf.
Habib Bamogo takes a shot. Save by Peter Brezovan.
The referee gives a free kick against Will Buckley for handball. Direct free kick taken by Carl Ikeme.
Pascal Chimbonda takes a shot.
Corner taken right-footed by El-Hadji Diouf, Joe Mattock manages to make a clearance.
Tommy Spurr is penalised for a handball. Gordon Greer takes the direct free kick.
Headed effort from inside the area by Giles Barnes misses to the right of the goal.
Booking Craig Mackail-Smith receives a caution for unsporting behaviour.
Craig Mackail-Smith gives away a free kick for an unfair challenge on Pascal Chimbonda. Direct free kick taken by El-Hadji Diouf.
Assist on the goal came from Liam Bridcutt.
19:04 Goal scored
Goal! - Craig Mackail-Smith - Doncaster 0 - 1 Brighton Craig Mackail-Smith finds the back of the net with a goal from inside the penalty box to the bottom left corner of the goal. Doncaster 0-1 Brighton.
Corner taken short by Will Buckley. Habib Bamogo fouled by Alan Navarro, the ref awards a free kick. Direct free kick taken by El-Hadji Diouf.
Free kick awarded for a foul by Simon Gillett on Will Buckley. Gonzalo Jara Reyes takes the free kick.
Adam El-Abd challenges Giles Barnes unfairly and gives away a free kick. Free kick taken by Simon Gillett.
Substitution Simon Gillett replaces Brian Stock.
Will Buckley gives away a free kick for an unfair challenge on Pascal Chimbonda. Free kick taken by Carl Ikeme.
Craig Mackail-Smith gives away a free kick for an unfair challenge on Habib Bamogo. Direct free kick taken by James Chambers.
James Hayter is flagged offside by the assistant referee. Indirect free kick taken by Gonzalo Jara Reyes.
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