It was Rangers’ first goal of the 2014/15 campaign and it also means Austin has now scored at every level in the English football league after ending the club's 315-minute Premier League drought.
Austin broke the deadlock on the cusp of half-time, striking sweetly into the top right-hand corner of Vito Mannone’s goal after Leroy Fer had peeled off at the back post to knock down Joey Barton’s corner.
Harry Redknapp's men were desperate for both goals and points after successive defeats by Hull, Tottenham and Burton, and had Austin to thank for a thumping first-half finish.
Redknapp had started Rangers' Premier League return favouring the 3-5-2 formation, but abandoned wing-backs in favour of 4-3-3 for the visit of Gus Poyet's Black Cats.
Sunderland started far the stronger but ultimately paid the price for failing to convert that dominance.
Adam Johnson slid in perfect through-balls for Steven Fletcher and Patrick van Aanholt, but neither man could convert - and that after left-back Van Aanholt had prodded wide to boot.
Summer recruit Fer struck a 25-yard thunderbolt against the crossbar with Mannone motionless between the sticks as QPR started to settle.
Lee Cattermole was fortunate to escape a red card after grabbing and kicking at Fer, just minutes after being booked.
Junior Hoilett shot straight at Mannone as the half-hour came and went, but then QPR took control.
Wes Brown pulled off a perfectly-timed tackle to deny Austin who was bearing down on goal, and then Mannone had to shut down the former Burnley striker in a one-on-one.
Mannone raced off his line to deny Matt Phillips as QPR scented their first goal of the new campaign in their fourth outing.
And just when the home fans expected another blank half, Austin delivered, firing high into the net from a well-worked corner.
Sunderland were still chasing their first league win of the campaign after two draws, but could at least draw on a morale-boosting 3-0 Capital One Cup midweek victory at Birmingham.
Poyet's side were visibly deflated by conceding just ahead of half-time, and struggled to generate any tempo after the turnaround.
Jack Rodwell and Fletcher had half-hearted efforts easily dealt with, before Robert Green turned a neat right-foot flick from Santiago Vergini round the post.
Clint Hill produced a fine sliding block to deny Connor Wickham after a dangerous low cross from Johnson.
Armand Traore wasted a fine chance after a smart through-ball from Bobby Zamora to ease late Sunderland pressure.
Green was then forced to pull out another fine save to deny Emanuele Giaccherini at the death.