Barton scored after only four minutes and striker Austin netted from the penalty spot to put Harry Redknapp's side firmly in control.
They surprised their opponents with a change of formation that had Middlesbrough on the back foot from the opening whistle.
Boss Redknapp opted for a 4-5-1 system with recent signing Niko Kranjcar, who was outstanding on his home debut, drifting in from the left.
It caused Boro problems immediately, although the early opener was created on the opposite flank.
Danny Simpson's right-wing cross was not dealt with and the ball broke to Barton, who fired through a crowded penalty area from near the edge of the box.
QPR continued to dominate and the home fans wanted a penalty when Alejandro Faurlin went down under a challenge from Frazer Richardson while attempting to collect Austin's pass.
Jason Steele then produced a good save to deny Barton - and was unlucky in the build-up to Rangers' second goal, which arrived 10 minutes before the break.
The Boro keeper kept out Austin's shot and the loose ball dropped to Gary O'Neil, whose follow-up was handled by Ben Gibson.
Austin duly stepped up to net his second penalty in as many matches, and struggling Boro - now without a win in seven matches - never looked like recovering.
They did rally early in the second half and substitute Lukas Jutkiewicz's shot brought a save from in-form QPR keeper Rob Green.
Albert Adomah was just unable to connect with Jutkiewicz's right-wing cross and later poked wide from 10 yards out as Tony Mowbray's men at least managed to create openings.
Otherwise, it was all Rangers and O'Neil had two efforts saved by Steele before curling wide from 20 yards.
Kranjcar's classy display earned him a standing ovation when he was substituted late on and suggested the Croatian will be a key player for the
London club as they pursue an immediate return to the top flight.
They are currently well on course and remain the only unbeaten side in the second tier.
The only note of concern for Redknapp, who is already without sidelined centre-back Nedum Onuoha, will be an apparent injury to skipper Clint Hill.
Defender Hill limped off with 12 minutes remaining after appearing to pick up a knock.