It had appeared as though Lasse Vibe's double had put Brentford on course for a routine three points at Loftus Road, but the Bees imploded at the death as the host earned a scarcely believable point.
Sergi Canos' long-range effort had tested Alex Smithies and Yoann Barbet put a free-kick just wide in a first half in which Brentford created the better chances.
The breakthrough came in the 52nd minute with Vibe's first goal since the last day of last season, the Danish striker controlling Nico Yennaris' pass in the area, spinning on the spot and smashing home.
Vibe had seemingly wrapped up the points when finished Romaine Sawyers' cut-back from the right byline nine minutes from time.
But Daniel Bentley's poor punch allowed Smith to head home in the 93rd minute, and incredibly Freeman bundled in after a bout of pin-ball to level the match shortly after.
Brentford moves up a place to 14th with a point, while QPR stays 16th.