QPR became the first side since October to take all three points from Home Park thanks to Richard Pacquette's second-half goal.
Pacquette struck in the 51st minute with a sweet shot after some fine approach play by Marc Bircham had set him up.
Plymouth threw every thing at their visitors after going behind but the range of defence, lead by the towering Daniel Shittu held firm.
The victory was overshadowed by a fiery end to the game with Rangers midfielder Lee Cook being given his marching orders in injury time for a foul on David Norris.
Tempers were still running high when ref Peter Walton blew for full time and there was an unsavoury scuffle at the entrance to the tunnel, involving both sets of players.
The incident seemed to have been sparked by an altercation between Rangers manager Ian Holloway and Plymouth captain Paul Wotton over a clash which preceded Cook's sending-off.
Referee Walton said that he would be mentioning the incident in his match report, although he would not be naming any individuals.
Plymouth manager Paul Sturrock declined to talk about the scuffle and Holloway played down the matter saying that: "No punches were thrown." Holloway also thought that Pacquette was unlucky not to have another goal after a first-half header from close range was ruled out for a marginal offside.
Pacquette's ruled out goal was followed by a thumping shot from 30 yards by his strike partner Brett Angell, which cannoned off the post with Plymouth keeper Romain Larrieu well beaten.
Argyle battered Rangers for the last half hour with Ian Stonebridge forcing Nicky Culkin into saving one of the few direct shots on goal and Marino Keith unluckily missed from a tight angle after rounding Culkin and Clarke Carlisle.