West Brom increased the pressure on QPR boss Mark Hughes as a fifth defeat in seven games left the west London team anchored at the bottom of the Barclays Premier League without a win.
Albion registered its fourth home win, their best start to a top flight season in front of its own fans since 1919.
Steve Clarke's side should have wrapped up the game in the opening half hour and could have doubled its two-goal advantage against a QPR side carved open almost at will during that spell.
But Taarabt, in his first start since the opening day of the season, dragged them back into the game and he demanded close attention from the Baggies back four.
Albion's acting skipper Jonas Olsson received a standing ovation from the home fans before kickoff after signing a new four-year contract -- and his side needed only four minutes to go ahead.
Baggies leading scorer Shane Long was too quick for Hill before delivering an inviting right-wing cross. Morrison timed his run perfectly to get behind Ferdinand and direct his header back across Julio Cesar into the corner of the net.
Albion looked sharp going forward and Long missed a golden chance to double the lead in a lightning counterattack.
Peter Odemwingie picked out the run of Morrison and his cross was perfectly weighted to find Long but from six yards out he fired over the bar.
QPR had no answer to West Brom's first touch football and a shocking error by Ferdinand gifted West Brom its second goal after 22 minutes.
Once again Morrison supplied the ball into the danger area and Ferdinand's attempted clearance fell straight to Zoltan Gera, who made no mistake from 10 yards out.
Albion right back Gabriel Tamas was booked for bringing down Taarabt before the QPR midfielder gave his side a lifeline with a stunning finish after 35 minutes.
Esteban Granero played the ball into the path of Taarabt on the edge of the box and he brought it under control before volleying past Ben Foster.
But Albion still threatened danger everytime it ventured forward and QPR needed a fine save from Cesar to deny Gera a second goal.
Peter Odemwingie's defense-splitting pass found the Hungarian international free inside the box but Cesar managed to deflect his shot past the post.
QPR skipper Park Ji-Sung was booked in first half injury-time for a lunge at Gera.
The visitors showed attacking intent at the start of the second period and Foster held a low drive from the impressive Taarabt.
Morrison had a shot deflected wide but Albion was guilty of sloppy play.
Granero had the chance to level matters but sliced his shot wide after more good work by Taarabt.
But Morrison almost capped another top performance with a second goal as his 35-yard drive flashed inches wide.
With five minutes left Mulumbu made it 3-1 after exchanging passes with Jara Reyes -- but QPR showed plenty of spirit and Granero reduced the gap again in injury time with a cool finish.