The Rs winger scored the only goal of the game as a rotated Blues team failed to overcome Harry Redknapp's struggling side in a shock result at Stamford Bridge
The away side barely troubled their opposition all night but Benitez's side were unable to capitalise on their dominance as, without Eden Hazard and Juan Mata, they struggled to create against a stout QPR defence.
The struggling side managed to make Chelsea pay for their profligacy as, after a corner broke to Wright-Phillips on the edge of the area, the winger made no mistake to find the bottom corner.
Rafa Benitez made five changes from the team that beat Everton; Marko Marin replaced Ramires to make his first Premier League start of the season, while Ross Turnbull, Ryan Bertrand, Victor Moses and Oscar all also started in place of Petr Cech, Ashley Cole, Hazard and Mata.
Meanwhile, the visitors also made four changes with Fabio, Shaun Derry, Esteban Granero and Junior Hoilett replacing Armand Traore, Djibril Cisse, Samba Diakite and Wright-Phillips.
With the away side sitting deep and Chelsea lacking the attacking creativity of Hazard and Mata, chances were few and far between for either side in a tame first half
The only real chance of the opening 45 minutes came just before the break, as an Oscar shot, deflected on its way by Lampard, required a smart save from Julio Cesar to keep the scoreline goalless.
After that fairly tepid start to the game, the opening of the second half brought a welcome increase in tempo as Chelsea began to create clear-cut chances; first, Moses was unable to meet a delightful Marin cross and then, minutes later, an Ivanovic header from a Marin corner clipped the bar on its way over.
The early second-half onslaught reached its peak with an excellent chance for Fernando Torres; a deflected David Luiz effort fell to the striker ten yards out but the Spaniard could only fire straight at Cesar.
The home side's pressure almost told after 65 minutes as, after sterling work from Moses in the penalty area, the ball fell to Lampard who, after duly firing into the bottom corner, was deemed just offside by the linesman.
As Chelsea were unable to capitalise on their pressure, the second half wore on and, with ten minutes remaining, a rare corner led to a shock opener for the away side.
After the corner was cleared at the near post, Taarabt deftly laid the ball into Wright-Phillips' path and the former Chelsea player found the corner of the goal from 25 yards out.
Chelsea's response was frenetic but chances remained hard to come by, the best chance falling to Ivanovic as he headed a Mata cross just over the bar.
QPR held on to claim their second league win of the season, but remain bottom on goal difference, while Chelsea remain fourth.