Barry Fry's men looked liked they had done a number on Rangers as Clive Platt's first goal for Posh seemed enough for an unlikely win, until Kevin Gallen popped up in injury time to claim a point for the hosts.
Ian Holloway's troops had the chance to go top of the Division Two table should they have beaten Peterborough, and although they dominated most of the first half - the visitors took the lead a minute before the break.
Substitute Tommy Williams swung in a deep cross that Platt nodded in from five yards out to give Posh a half-time lead.
Fry's men did well to keep Rangers quite in the second half, until R's defender Clark Carlisle suffered a nasty injury moments after Holloway had made a treble substitution.
Carlisle hobbled up front and caused problems as the hosts piled forward in search of a leveller - although Kevin McLeod and Gallen missed guilt-edged chances.
QPR keeper Nick Culkin was lucky to stay on the pitch as he came racing out of his goal and nearly took Platt's head off with a high challenge, but the presence of defenders behind him meant he received just a yellow card.
Gallen then popped up to rescue a point for the hosts, preserving their unbeaten home record, which at least keeps them in touch with the top two.
Hartlepool were also held at home to a 1-1 draw by Blackpool, despite the hosts taking the lead after 51 minutes through Hugh Robertson.
Mike Sheron gave Steve McMahon's men a point at Victoria Park as he levelled the score with 16 minutes left to play.
Division Two:
Hartlepool 1-1 Blackpool
QPR 1-1 Peterborough
