The Rangers revival faltered on Boxing Day, as Luigi De Canio's men fought hard, but conceded a late, late goal to lose 2-1 at Plymouth.
The R's took the lead at Home Park on 19 minutes when Rowan Vine slotted home at the far post following good work by Akos Buzsaky and Martin Rowlands.
But right at the start of the second half Argyle drew level with a Sylvan Ebanks-Blake spot-kick after Simon Walton was adjudged to have handled in the box.
And the R's had to swallow a bitter pill of defeat when Ebanks-Blake netted in the fourth minute of injury time following a Peter Halmosi corner.
The visitors were left devastated at the final whistle after fighting so hard but, in the end, having nothing to show for their efforts.
De Canio made two changes to the side that started against Colchester on Saturday, with Rowlands and Walton coming in at the expense of Dexter Blackstock and Damion Stewart.
Stewart was forced to sit this one out owing to the red card he picked up against the U's, allowing Walton the opportunity to make his first competitive start since his summer switch from Charlton.
Meanwhile Rowlands overcame illness to feature, with Blackstock dropping to the bench.
Plymouth made three changes in the wake of their defeat at Crystal Palace, with Paul Connolly, Lilian Nalis and Ebanks-Blake replacing Dan Gosling, Gary Sawyer and Jermaine Easter respectively.
The R's came into this match on the back of a good run of form but it was the hosts who had the first chance after four minutes.
Connolly won the ball from Rowlands and found David Norris just inside the Rangers half. The Argyle winger was allowed to race 30 yards before firing a low shot inches wide of Lee Camp's right-hand post.
On ten minutes, Argyle again went close to unlocking the R's defence. Peter Halmosi's ball from the left was excellently dummied by Ebanks-Blake for the on-rushing Barry Hayles, but Camp was able to snuff out the chance.
But it was the visitors who took the lead in the 19th minute with their first real chance of the game.
Buzsaky - playing against his parent Club - found Rowlands down the left with a fantastic half-volley pass, and the R's wide man got to the by-line before pulling it back across the face of goal.
The chance looked to have gone when no-one was able to get a touch, but Vine popped up at the far post to slide the ball home, to the delight of the travelling R's supporters.
Plymouth had the chance to restore parity on 26 minutes when Halmosi's deep cross from the left found David Norris but his looping header was easily gathered by Camp.
The hosts were having the majority of possession but Rangers - governed by the inspirational Walton - looked comfortable with whatever Paul Sturrock's men could throw at them.
Argyle had a great chance to draw level on the half-hour mark, however, when Halmosi's delightful free-kick from just outside the Rangers box was met by the sliding Nalis, but Camp was equal to it, saving from six yards with his feet.
For all their possession, the hosts couldn't find a way through in the opening half and the sides went in at the break with Rangers leading 1-0.
Three minutes after the interval, Argyle were given the perfect opportunity to draw level when Walton was adjudged to have handled in the area. Halmosi cut in from the left before firing goalwards. His effort hit the R's defender on the arm from close range and, after a long think, referee Steve Bratt pointed to the spot.
Ebanks-Blake made no mistake from 12 yards, firing low to Camp's right to score his tenth goal of the season.
The game went through a scrappy spell following the equaliser with three yellow cards being brandished by the referee in a matter of minutes as the match threatened to boil over.
With a little over 20 minutes remaining, De Canio replaced Rowlands with Marc Nygaard, putting Vine wide left. And shortly after, Buzsaky's return to his 'current' Club came to an end when he made way for Blackstock as the R's looked to hit Argyle on the break as the hosts searched for a winner.
And Blackstock, who previously enjoyed a loan spell at Home Park, was soon into the thick of the action as he won a corner for the visitors.
From Ainsworth's delivery, it was Blackstock who rose highest to power a header goalwards from eight yards, only for Romain Larrieu to deny him with a decent save.
At the other end Lee Hodges went close with a deft header from a Halmosi corner, and as the game seemed to be drawing to a close, the hosts had one final chance.
Halmosi's delivery caused panic in the R's six-yard box and, after initially hitting the bar, Ebanks-Blake was on hand to smash home a late, late winner.
To add insult to injury, Mikele Leigertwood was sent off for dissent after the final whistle.
Plymouth Argyle: Larrieu, Connolly, Nalis, Timar, Norris, Ebanks-Blake, Hayles (Easter, 73), Halmosi, Hodges, Seip, Abdou (Martin, 73).
Subs: Fallon, Sawyer, Gosling.
Goals: Ebanks-Blake (49), (90)
Bookings: Ebanks-Blake (52), Nalis (86), Easter (88)
QPR: Camp, Barker, Bolder, Buzsaky (Blackstock, 78), Ainsworth, Rowlands (Nygaard, 67), Walton, Malcolm, Vine, Rehman, Leigertwood.
Subs: Cole, Moore, Kanyuka.
Goals: Vine (19)
Bookings: Buzsaky (30), Rowlands (45), Ainsworth (51), Walton (52), Bolder (70), Nygaard (76), Leigertwood (90)
Red Cards: Leigertwood (90)
Referee: Mr S. Bratt
Attendance: 16,502 (QPR fans: 698)
