Clarke Carlisle's 43rd minute goal gave Leeds the lead and rewarded their first-half dominance as the defender struck the ball just inside the near post after his first attempt rebounded to him.
But Brighton gatecrashed the party and held on to a point despite the 88th minute dismissal of Charlie Oatway for kicking out at Leeds midfielder Simon Walton.
Brighton gave a debut to goalkeeper David Yelldell, on loan from Blackburn, while Adam Virgo and Mark McCammon also came in.
Iceland midfielder Gylfi Einarsson made an impressive first start for Leeds who welcomed back Brian Deane, Walton and Aaron Lennon.
Leeds came close to making the perfect start when Icelandic international Einarsson almost marked his full debut with a goal inside the opening minute, meeting Gary Kelly's cross with a bullet header which demanded a fine save from Yelldell.
Lennon's pace repeatedly troubled Brighton's defence and his trickery took him past Butters and Daniel Harding but Deane lost his footing in the goalmouth.
Brighton claimed they should have had a penalty when Paul Reid fell to David Healy's mild challenge, but referee Mike Thorpe disagreed.
Albion found it more difficult to get out of their own half and Butters made up for his earlier mistake by clearing Lennon's drive off his own line as Leeds continued to dominate without finding a breakthrough.
Carlisle's goal was no more than Leeds deserved but Brighton began the second half much brighter in more ways than one.
Keeper Yelldell changed into a bright pink shirt, much to the amusement of the Leeds fans who teased him mercilessly.
Adam Hinshelwood produced a crucial challenge on Simon Walton moments after the interval as the midfielder took aim at Yelldell's goal.
Leeds keeper Neil Sullivan was also at his best to claw a swerving shot from substitute Gary Hart away from the top corner of the net.
Sullivan was then forced to do the same to a drive from Leon Knight less than a minute later as the visitors sensed a way back.
Yelldell produced the save of the match to keep out Kelly's shot on the hour mark and it was to be vital.
Butters was left unmarked to meet Paul Reid's cross as Sullivan appeared to lose his footing to prevent the equaliser.
Brighton deserved that but Leeds are making a habit of failing to hold on to a lead and they have now won only one of their last seven home matches.
Eirik Bakke made his comeback for Leeds after a long injury absence and his first contribution was a fierce challenge on Nathan Jones which earned him a booking and provoked several players to square up to one another in the aftermath.
MAN OF THE MATCH: Aaron Lennon (Leeds). The winger's pace had Brighton's defence dancing on hot coals.