Jamie Mackie cancelled out Danny Graham's first-half goal to secure a point for QPR in a gripping game at the Liberty Stadium.
Mackie was alert to pounce on Leon Britton's poor header from Paddy Kenny's long clearance on 58 minutes.
Graham's exquisite first-half strike had given Swansea the lead, although QPR claimed he handled the ball.
Swansea were denied a penalty when Graham was felled in the area while Michel Vorm saved from Adel Taraabt.
With the sides hovering precariously above the relegation zone, both went for the win.
The draw ensured that QPR, who next travel to Arsenal, ended a sequence of three defeats. But it meant that the Swans have now won just once in their last eight games.
Early on, it was the visitors, with Adel Taarabt in their starting line-up, who set about their task with purpose.
A cross from Joey Barton caused problems for the Swansea defence with headers from Heidar Helguson and Mackie putting pressure on in-form Swansea keeper Vorm.
Swansea were slowly finding their rhythm with Graham wasting a half chance following the game's first corner and then failing to connect with Wayne Routledge's cross.
But on 17 minutes another Routledge cross found Graham, who controlled the ball on the edge on the area before turning and firing low into the bottom left-hand corner, a quality finish for his sixth goal of the season.
Rangers, in particular manager Neil Warnock, felt aggrieved the goal was allowed to stand, arguing that Graham had controlled the ball with his arm before shooting.
Graham, a QPR target in the summer before opting to leave Watford for Swansea, was denied a second goal when, following a cross from Scott Sinclair, his effort was blocked by Clint Hill.
At the other end Vorm was forced to make an acrobatic save to deny Barton's long-range effort after Swansea had failed to clear following Taarabt's free-kick.
It was developing into an end-to-end encounter and as the first half came to an close Helguson headed two successive efforts over the crossbar.
If Swansea had the better of the opening half, it was the visitors who controlled the early stages of the second with Taarabt, who scored twice in QPR's 4-0 Boxing Day thrashing of Swansea last season, firing a volley wide.
In response, good work from Joe Allen created an opportunity for Routledge, but the former QPR man could only toe-poke the ball wide of the post.
That was to be Routledge's final contribution as he was replaced by Nathan Dyer with Luke Moore replacing Angel Rangel, who had been injured during the first half.
But within a minute of the double substitution, Swansea were caught napping with the alert Mackie levelling for the visitors.
He pounced on a poor header by Britton following Kenny's long clearance - the midfielder directed the ball dangerously towards his own goal - and the Scotland international brushed off the challenge of Ashley Williams to fire past Vorm.
Mackie, who had scored in the previous game against Sunderland, continued to cause problems and it was only the quick response of Vorm coming off his line which halted his run.
Swansea felt they should have been awarded a penalty on 73 minutes when Graham fell under the challenge of Armand Traore, but referee Lee Probert waved away their protests.
Vorm was forced into another good save when he tipped Taarabt's curling effort round the post before Williams had to head clear Traore's cross.