Two second-half goals from Adel Taarabt, the latter of which was a superb solo effort, made it 17th time lucky for the Loftus Road club.
Harry Redknapp still has a huge task to save QPR, who had a late scare through Mladen Petric's goal, from relegation but they are at least off the bottom of the table.
Last weekend's draw at Wigan Athletic saw them break the record for the longest winless start to a Premier League season, with chairman Tony Fernandes this week admitting the season has been "nothing short of a disaster".
The Rs have, though, shown signs of improvement since Redknapp succeeded Mark Hughes at the helm, following up three successive draws with a first win on Saturday - thanks in no small part to man of the match Taarabt.
After a disappointing first half, it was QPR supporters with something to shout about when the game restarted after the break.
Stephen Kelly came on for the seemingly injured Sascha Riether when play resumed, with QPR taking just seven minutes to score their first goal against Fulham since 1983.
Like so many times before, Taarabt made a burst forward but this time his strike took a lucky deflection of Brede Hangeland, wrong footing Mark Schwarzer and trickling home.
The playmaker was booked for his celebrations but it could not stop QPR's momentum, with Djibril Cisse curling just wide in the 60th minute after Chris Baird was dispossessed.
Fulham were rarely threatening the hosts, who deservedly got their second when Taarabt burst through in the 68th minute.
After picking up the ball just inside the Fulham half, the midfielder went past Hangeland and showed a few neat touches, before rolling past Schwarzer with the outside of his right foot.
Petric ensured a nervy ending when his strike deflected in off Jamie Mackie's outstretched leg but QPR held on.