Rangers have now gone nine matches without a win and the failure to make home advantage count has left Southampton rooted in the Championship's bottom three.
After drawing with Derby at St Mary's in midweek, another home failure means Southampton face a massive task to escape relegation.
If might have been different if Southampton had accepted a third minute chance when Jason Euell broke through with only the goalkeeper to beat but his control let him down.
Instead Rangers, without several key players, might have gone in front in the 12th minute when a deflection off Southampton defender Chris Perry was goalbound until goal keeper Kelvin Davis stretched to concede a corner.
Big Damion Stewart, a key figure in the Rangers defence, should have got his name on the scoresheet in the 22nd minute but he headed over from three yards following a corner by Liam Miller.
Southampton pushed players forward in a desperate bid to record a vital win and twice had chances in the last 11 minutes to clinch the victory.
After 79 minutes, Andrew Surman mis-hit a shot from ten yards with only goalkeeper Radek Cerny to beat and then in injury time, Surman again saw his effort cleared from near the line by Stewart.
QPR manager Paulo Sousa introduced new loan signing Adel Taarabt late in the second half and in injury-time his right-foot shot was saved full stretch by the diving Davis.
Referee Michael Jones was a busy man booking Kaspars Gorkss in the first half and in the second showed yellow cards to Lloyd James, David McGoldrick and man-of-the-match Stewart all for fouls.