Austin was on target in the 22nd minute, heading home from Joey Barton’s quickly-taken free-kick.
The friendly came too early for new signing Rio Ferdinand, as Rangers effectively fielded two teams – a mixture of youth and experience – in either half.
There was play at both ends inside the opening stages, though Rot-Weiß Erfurt enjoyed the better chances.
This was Erfurt’s final fixture of their pre-season schedule and that was evident in terms of the home side’s sharpness.
Christian Falk missed a plethora of chances for the hosts in the first period, with both Rob Green and Jamie Sendles-White notably denying the home forward.
For Rangers, Austin had an effort ruled out for offside before eventually giving the R’s a legitimate lead in the 22nd minute.
Barton’s quick free-kick was to a tee for the former Burnley man, who headed past Philipp Klewin.
Erfurt continued to press – Falk again often in the thick of the play.
But it was QPR who should have extended their lead on the stroke of half-time. Michael Doughty freed Austin with a lovely, lofted pass but the forward was denied by a block as he bore down on goal.
Rangers used the remainder of their substitutes – 10 in total – for the second half, with only Armand Traore, brought on in the first period, left on.
The final 45 minutes largely made for a close spectacle.
Ale Faurlin had an effort ruled out for offside in the 58th minute, while a cross from the right forced Joe Lumley into a tip over the crossbar three minutes later.
Lumley was called into action again in the 69th minute, palming away a long-range blast, before Clint Hill produced a last-ditch challenge to thwart Andreas Wiegel.
However, that was as good as it got, as the game petered out – and Rangers held on to claim victory in their opening pre-season match.
QPR first half: Green, O’Neil, Dunne, Barton, Austin, Wright-Phillips, Granero, Doughty, Gibbons (Traore 28), Sendles-White, Ehmer.
QPR second half: Lumley, Simpson, Traore, Hill, Donaldson, Onuoha, Petrasso, Faurlin, Henry, Zamora, Sutherland.
Goals: Austin (22)