Clarke Carlisle and Kevin McLeod's late show sent QPR into second spot after hard-working Wrexham made the home side sweat.
Carlisle struck from Kevin Gallen's corner after 67 minutes to settle Rangers' nerves after Lee Camp kept them in the match with a string of fine saves.
And McLeod sealed it three minutes before full-time with a superb solo effort from 15 yards to keep Rangers nipping at the heels of league leaders Plymouth.
But Wrexham will be kicking themselves for going home empty-handed after dominating for much of the match.
Chris Armstrong was first to give the home side a fright on 18 minutes when his spectacular overhead kick went just wide.
And Camp was on hand to first block Jim Whitley's close-range shot on 28 minutes, then keep out Chris Llewellyn's goalbound rocket just before the break.
Nervy Rangers, who have not lost at home in the league since March last year, made hard work of things and failed to register a single shot on target until Carlisle's bundled effort.
Paul Furlong should have broken the deadlock for Rangers just after the break but he fired just wide from outside the area with only keeper Michael Ingham to beat.
And with resurgent Rangers on the attack, Furlong missed two more chances midway through the second half to have the home fans on the side's back.
But left winger McLeod held his nerve late on after racing up from halfway to slot past Ingham into the bottom corner to hand Ian Holloway's side the three points.