Austin scored the only goal to sink Sunderland in August - the solitary triumph of the season for Harry Redknapp's men as they headed into Monday's Loftus Road encounter with an out-of-sorts Villa side.
Despite being on the defensive during the opening exchanges, Rangers led when Austin - who first came to prominence with non-league Poole Town - marked his 200th professional appearance with his 105th career goal in the 16th minute.
Christian Benteke went closest to levelling for Villa before Austin ensured his former club Burnley replaced QPR in 20th position after impressive work from Chile international Eduardo Vargas.
Three points were vital for QPR ahead of games against title favourites Chelsea and Manchester City, while Villa - whose impressive start to the campaign included a win over Liverpool at Anfield - have now lost five consecutive matches without scoring since Paul Lambert agreed fresh terms at the club.
Rob Green returned to replace understudy Alex McCarthy in goal for QPR, while Vargas replaced Nedum Onuoha and his compatriot Mauricio Isla reverted to right-back as the ex-Manchester City defender sat out with hamstring trouble.
An ankle injury to Alan Hutton meant a first appearance of the season for Villa right-back Matt Lowton - one of four changes made by manager Lambert following their 3-0 loss to Everton.
Villa made the most impressive start, with Green doing well to get behind powerfully struck efforts from Ashley Westwood and recalled fellow midfielder Carlos Sanchez.
But QPR surged ahead against the run of play in the 16th minute when Bobby Zamora chested down for Austin to send a wonderful 20-yard effort whistling into the bottom left corner.
The QPR backline were kept busy as Benteke saw a header sail narrowly wide before Green had to be sharp to deny Andreas Weimann and Yun Suk-young produced a timely 34th-minute block to deny the Austria forward.
Villa's attacking efforts continued after the interval as Benteke towered above the QPR defence to head down a 55th-minute set play for Ciaran Clark but the defender could not scramble home under pressure.
Zamora made way for Junior Hoilett in the 62nd minute and the winger lent renewed impetus to the QPR attack, clipping a curling effort against the post.
The change in momentum proved decisive as Sanchez carelessly gave away possession in the 69th minute for Vargas to charge down the right flank, Austin finishing his low cross with aplomb at the near post.
Villa's frustrations were compounded as substitute Joe Cole clumsily got in Benteke's way as a sight of goal opened up and Green produced a fine double save to extend Villa's toothless run and secure a rare clean sheet.
