A late, late winner from QPR skipper Nedum Onuoha was enough to earn Neil Warnock a win at Madejski Stadium at the very end of a closely-contested affair that it seemed the Royals would gain something from throughout.
Michael Hector came close to breaking the deadlock in both halves, heading across the face of goal in the first then nodding just over in the second. Nick Blackman came even closer with a free kick that beat Green but clattered into the crossbar. Grant Hall directed a late headed effort over from close range, while Hal Robson-Kanu dragged a left-footed effort just wide - but it was a 90th minute winner that harshly separated the sides.
Steve Clarke made three changes to the side that lost at Nottingham Forest, bringing in Anton Ferdinand for the injured Paul McShane at the back, introducing a fit again Garath McCleary to his eleven and starting Alex Fernandez in midfield.
After a cagey opening, Reading caught glimpse of the goal first and it was a good chance. Paul Konchesky pulled Garath McCleary back and conceded a free kick which Norwood delivered towards the far post. Michael Hector came in round the back and got his head to it, but nodded the ball across the face of Rob Green's goal and wide.
Moments later an identical free kick from Norwood fell to the feet of Williams inside the box but he couldn't control the ball inside the box and the danger fizzled out.
At the other end, Rangers looked dangerous with the pace they possessed in attack, but Alex Fernandez led a counter attack for the home side 20 minutes in, only for his final ball to fizz just to far in front of the approaching Vydra in the penalty area.
With 25 minutes gone, two good chances came at either end in the space of 30 seconds. The first saw Junior Hoilett force Al Habsi into a comfortable save with a well-struck left-footed effort. Then at the opposite end, Nick Blackman got in behind the back four and with Vydra an option to his left he shot but dragged his effort wide of the left upright.
Leroy Fer picked up the first caution of a niggly game when he scythed Ollie Norwood down in midfield, then Hector swept a lovely crossfield ball in search of Gunter only for it to skip up off the wet surface and go out for a Rangers throw.
Grant Hall saw yellow for breaking up a Reading counter attack with an arm as Fernandez looked to dink the ball into the path of McCleary bursting forward, then Fernandez blocked a Sandro effort on the edge of the box.
And there was time for McCleary to rifle a low cross in from the right and then Andrew Taylor to thunder a left-footed effort over from the edge of the box before referee Andrew Madley brought an end to a goalless first half.
Half-time: Reading 0 QPR 0
The second period began with half-sights at goal at either end, McCleary's low cross cut out by Onuoha, then Hector chested the ball into the feet of Sandro before charging down the midfielder's first time cross.
Hector had enjoyed the best chance of the first half, and when a deep free kick fell to him again at the far post he tried to flick the ball home only for Onuoha to get a touch to it and deflect it wide. From the corner, Hector rose highest and placed a powerful header inches over the crossbar.
The hosts came even closer just after the hour, Nick Blackman winning a free kick and thundering a swerving effort past the QPR wall, beyond the statuesque Green but against the QPR crossbar.
Meanwhile, Neil Warnock introduced Charlie Austin to the field, but it was Vydra who came close to scurrying onto a weak back header from Hall - Green slid out to the very edge of his box to deny the Royals striker the first touch.
Hal Robson-Kanu returned from injury with a little more than a quarter of an hour of the game remaining, then good work from McCleary and Blackman saw the latter hook a high cross into the box - but Green gathered it cleanly under pressure from Vydra.
Williams almost picked out a superb ball for Blackman in space, but Konchesky did well to get there first with a sliding challenge that denied the Royals striker a clean route to Green's goal.
QPR's best chance of the encounter came with ten minutes left, when a floated free kick on half way was nodded on and Hall had an opportunity to head it goalwards from close range, but he could only direct his effort over the bar.
Robson-Kanu then got the ball to feet in space in the QPR box after a threaded ball through from McCleary. But the substitute arrowed wide of the far post with a left-footed effort. Austin almost stole in ahead of Al Habsi when a free kick from deep was headed on into the six yard box, but the Omani stopper came to collect it well.
Rangers took the lead in the last minute of normal time though to steal all three points. A corner to the far post wasn't cleared and Nedum Onuoha found a way through a crowd of bodies with a downward header that sent the away fans home happy.
Full-time: Reading 0 QPR 1Reading
: Al-Habsi, Gunter, Taylor, Hector (c), Ferdinand, Fernandez (Robson-Kanu 73), Norwood, Williams, McCleary, Vydra (John 80), Blackman (Sa 80).
Subs: Bond, Obita, Cooper, Hurtado.
: Green, Perch, Konchwesky, Onuoha (c), Hall, Sandro, Faurlin, Petrasso (Austin 64), Fer, Hoilett (Chery 76), Phillips.
Subs: Smithies, Luongo, Henry, Angella, Toszer.
Yellow: Fer, Hall
Referee: Mr A Madley
Att: 16,365 (1,367 away)