After an impressive 3-1 win over Bristol City in its opening EFL Championship match, Leeds appeared set for another routine win at Elland Road against a Forest side that had failed to win its first match of the new season.
But despite dominating possession and chances, Marcelo Bielsa's men were unable to make the best of their opportunities, and paid the price in the 77th minute when Lewis Grabban bundled home an equaliser after Pablo Hernandez had given the home side the lead just before the hour.
Patrick Bamford had several chances to put Leeds out of sight before Hernandez's goal, but couldn't hit the target, one mis-hit volley coming back off the bar in the second half before a chip over Forest keeper Arijanet Muric was sent wide with the goal gaping.
Given its weight of possession, Leeds appeared comfortable with a one-goal lead, and second seemed only a matter of time, but it was Forest that stole the initiative, albeit controversially.
The visitors launched a break down field in which Grabban appeared to clearly foul his marker, but the referee's assistant didn't call play back, and from a resulting corner, Grabban was able to force home a scrappy and unlikely equaliser as Leeds's defence failed to clear what would turn out to be Forest's only shot on target.
The home side was further frustrated in the 84th minute when Jack Robinson appeared to kick straight through Stuart Dallas in the Forest penalty box, but again nothing sinister was seen by the officials.
Leeds begins its Carabao Cup campaign in midweek against Salford City before getting back into league action at Wigan Athletic next weekend. For Forest, Fleetwood awaits in the first round of the cup before what is likely to be a more testing visit from Birmingham City in the league.