Walcott fires early Gunners winner
Loic Remy was denied by a fine Wojciech Szczesny save as the Gunners held on for a fifth successive away win saw to move two points clear of Chelsea, having played two games more, and Tottenham, who play at Stamford Bridge on Wednesday.
Walcott, playing in the central role he has long coveted, troubled Rangers throughout and hit the post midway through the first half.
Arteta then threaded the ball through a static defence to Walcott, who had ghosted in behind and fired in a shot across goal and under Robert Green.
Arsenal's intricate play continued but QPR were also fashioning openings, but the final ball was often lacking. Walcott came close to his second when he breached the defence once more to latch on to a Rosicky pass and saw his shot turned on to the post by Green.
Andros Townsend was Rangers' most lively player and twice troubled Szczesny early in the second half. Green parried clear a swerving Santi Cazorla drive and then turned a Walcott shot around the post.
Seven minutes from time, QPR broke, with Zamora crossing for Remy, whose shot on the turn appeared destined for the far corner, only for Szczesny to save at full stretch. That was as good as it got for QPR as Arsenal saw out victory.