QPR midfielder Martin Rowlands scored his fourth league goal of the season to save Ian Holloway's side from slumping to their only second defeat in 18 games.
Rowlands snatched a share of the spoils with an equaliser 11 minutes from time to cancel out Sam Parkin's 39th minute opener.
Swindon striker Tommy Mooney wasted the chance to record a first half hat-trick with a host of uncharacteristic misses.
The 32-year-old former Aston Villa and Birmingham ace should have opened the scoring after just 20 minutes after being played through by Parkin, but inexplicably blazed over from the edge of the area with only keeper Chris Day to beat.
Mooney wasted another chance to put Swindon in front 11 minutes later when he headed against the crossbar from six yards after Steve Robinson had crossed from the right.
Rangers produced few goalscoring opportunities in a frantic first half and the luckless Mooney almost made the visitors pay for their sloppiness seven minutes before the break.
The veteran frontman headed Robinson's corner towards goal only to see Rangers defender Gino Padula divert his shot onto the bar.
Ian Holloway's side were not so lucky 60 seconds later when Parkin headed Swindon into a deserved lead.
The former Chelsea trainee headed past Day from 12 yards after racing on to Andrew Gurney's pass.
Rangers looked a more confident side in the second half and could have been level within 11 minutes of the restart when Tony Thorpe shot against the post from 12 yards out.
Striker Thorpe should have done better a minute later when he shot straight at goalkeeper Rhys Evans after strike partner Kevin Gallen put him through with a neat flick.
Rangers got their just desserts 11 minutes from time when Rowlands seized on a defensive error from Jerel Ifil to pull the scores level with a fierce right-foot shot from ten yards.