Championship -03/11/2009
Palace hold QPR
Hungary international Buzsaky gave the R's a half-time lead after Danny Butterfield was judged to have brought down Abel Taarabt, but when Freddie Sears went down under Fitz Hall's challenge, Ambrose levelled the proceedings.
The point means Rangers climb into the play-off places, while Palace will take heart from another hard-earned away point as they bid to rise up the table.
With the top six in their sights, Wayne Routledge tested Julian Speroni with an early effort, but it was Palace who settled the quicker as they frustrated their hosts.
Rangers looked unsure how to break down the red and blue wall in front of them but when the referee pointed to the spot after Butterfield's challenge on Taarabt, Buzsaky waited for the protests to die down before sending Speroni the wrong way.
QPR almost grabbed a second on 30 minutes when Alassane N'Diaye sliced the ball goalwards, but Palace's immediate counter-attack ended with Stern John hitting the outside of the Rangers woodwork.
Routledge should have done better when he was put one-on-one with Speroni three minutes before the break, while Darren Ambrose almost levelled from close range with seconds of the half remaining.
Neil Danns fired a warning to the hosts minutes after the restart following sloppy Rangers defending, only for Alejandro Faurlin to force Speroni to tip over at the other end.
Taarabt came close to adding a second when his effort was deflected over by Johannes Ertl, but it was Palace who immediately grabbed the all-important second.
Sears attacked Hall and when the West Ham loanee went down, the referee had no hesitation in pointing to the spot.
Ambrose clinically sent Radek Cerny the wrong way.
As Rangers looked to regain the lead, Taarabt tried two long range efforts that almost paid dividends, before Busaky's 18-yard free kick was superbly pushed round the post by Speroni.
Ben Watson headed narrowly wide from the resulting corner, but it was Alan Lee who could have wrapped things up for Palace with a header that was well saved by Cerny.
As Rangers pressed, sub Rowan Vine came close while Alan Lee was lucky not to be red-carded after seemingly punching Kaspars Gorkss with seconds remaining, but Palace held on for the point.