Substitute Robert Snodgrass rescued a point for Leeds as a close-range finish on his return from injury pegged back 10-man Crystal Palace.
Chris Martin gave the Eagles an early lead as he cut in and fired into the bottom corner of Andy Lonergan's goal.
But Sean Scannell got a second yellow card for a clumsy challenge on Danny Pugh to leave the hosts a man down.
Snodgrass tucked away Ross McCormack's pass before Julian Speroni's save denied Mikael Forssell a Leeds winner.
Snodgrass was a surprise inclusion in the Leeds squad after having surgery on his appendix just two weeks ago and the Scotland international justified his place on the bench by netting the equaliser within seven minutes of his introduction.
Palace were victorious in the first leg of the Carling Cup semi-final against Cardiff on Tuesday night but they have been inconsistent in the Championship of late.
They began the stronger of the two sides, with Martin finding the net after just six minutes.
Leeds responded well, with Pugh blasting Adam Clayton's corner over the bar from six yards, before Speroni was called upon to save well from Clayton and Tom Lees to preserve Palace's lead.
Scannell had already been cautioned for a foul on Andros Townsend when he clattered into Pugh to earn his marching orders on the stroke of half-time.
Leeds pressed forward after the break and McCormack and Lees both went close before Snodgrass levelled.
The visitors could have departed Selhurst Park with all three points as Snodgrass, Pugh and Clayton threatened from distance before Speroni blocked Forssell from close range.
Crystal Palace boss Dougie Freedman on Sean Scannell's red card:
"I felt the decision was made too quickly and looking back, it was probably not a sending off.
"But the referee has to make these decisions in real time and the game is quick today. I think that's why the few seconds after the referee blows the whistle, is very crucial to them.
"It is unfortunate but we don't look for excuses. We got on with it and got a good point."
Leeds assistant manager Glynn Snodin:
"We thought we did well. We tried to get the ball out wide and make the extra man count.
"We got the goal in the second half and thought we could push on and go and win the game.
"But Palace are good on the break, even with 10 men, and when Wilfried Zaha came on.
"They came out in the first half and put us on the back foot. They had a few early shots and then went 1-0 up after six minutes, like they did last season, so it was a good point for us."