Rangers, heavily dependent on Austin this season, struggled before their top scorer opened the scoring by finishing emphatically on 55 minutes after Clint Hill's lofted ball forward had been flicked on by Niko Kranjcar and then Andy Johnson.
The Terriers were impressive and looked set to secure a deserved point when recent signing Nahki Wells levelled midway through the second half, heading home a cross from Adam Hammill.
But striker Austin's header with 12 minutes remaining from Benoit Assou-Ekotto's right-wing corner proved decisive.
The first half was very open. Johnson almost put QPR ahead and they hit the woodwork twice, with Huddersfield also missing excellent chances to score.
Rangers boss Harry Redknapp had made a major tactical change, pairing Austin and Johnson, whose header from Kranjcar's early corner was cleared off the line by Hammill.
Without the injured Joey Barton, Redknapp opted for a diamond midfield, with Karl Henry in front of the back four and Kranjcar supporting the two strikers.
They struggled to adapt in the opening 45 minutes and Town's Danny Ward fired over after being found by Adam Clayton, and then squandered a golden opportunity by dragging a shot wide having been set up by Oliver Norwood.
Huddersfield continued to cause problems and keeper Rob Green uncomfortably pushed over Norwood's free-kick before saving Wells' header.
And QPR had another lucky escape when the unmarked Jonathan Hogg shot tamely at Green despite having plenty of time and space after collecting Ward's pass.
Redknapp's side were at least able to rely on Kranjcar's set-piece deliveries, and another corner from the Croatian led to first Austin and then Henry heading against the bar.
They have certainly been able to rely on Austin, whose well-taken first goal 10 minutes into the second half settled the home fans' nerves.
But Huddersfield have acquired their own clinical forward in Wells and the Bermuda international has now scored twice in as many games since his move from Bradford.
Rangers, to their credit, responded strongly to that setback and substitute Matt Phillips brought a fine save from keeper Alex Smithies before Austin eventually restored his team's lead.
The closest Town came to another equaliser was a header from substitute James Vaughan that was comfortably gathered by Green.