QPR goalkeeper Pierce Charles pulled off a remarkable double save in injury time to stop West Ham moving top of the Championship and earn his side a point.
The below-par Hammers looked set to complete a comeback victory after Pablo was pulled down in the area by Amadou Mbengue.
But Charles dived low to his left to keep out Jarrod Bowen's penalty and then reacted quickly to keep out Arne Engels' effort from the rebound.
QPR had taken the lead from the spot in controversial fashion after Tomas Soucek was harshly adjudged to have fouled Paul Smyth. Soucek appeared to get the ball in a tackle that was outside the area.
Nicolas Madsen rolled home the penalty before Bowen equalised for West Ham in the 70th minute with their first shot on target.
The home side rallied late on to try and claim all three points but Charles' heroics mean West Ham stay in second place, while QPR move up to fifth.
QPR had started brightly and got their reward when Soucek, playing his first game of the season for West Ham, gave the ball away to Smyth inside his own half and raced back to make what appeared to be a fair challenge but referee Ruebyn Ricardo pointed to the spot.
West Ham enjoyed more possession after going behind but rarely threatened an organised QPR team, who have conceded just four goals on the road this season and boast the second best defensive record in the division.
The visitors almost doubled their lead shortly before the break when they sprung a quick counter attack, but Rayan Kolli's curling effort from the edge of the area towards the far corner was well saved by Mads Hermansen.
After a flat display for much of the night by West Ham, Bowen single-handedly dragged his side back into the contest, cutting inside from the right and firing home his seventh goal of the season at the near post after his initial effort had been blocked.
That equaliser lifted West Ham and Charles was forced into two fine saves from Joel Piroe and Bowen in quick succession late on.
But his finest moment came in the 91st minute, with his double save.
It maintained QPR's unbeaten league record away from home this season, while the Irons could slip out of the automatic promotion places by the end of the weekend's action.