The England international broke the deadlock within twenty seconds of kick-off; a goal that - with the Rs proving unable to overturn the one-goal deficit - pushed Arsenal two points clear of top-four rivals Chelsea and Tottenham.
And with Spurs and the Blues facing each other in their game in hand on Wednesday Walcott noted the increasingly pressure, which he believes his team-mates can thrive under.
"Can we win our remaining games? Without a doubt," he told reporters.
"The way we're playing as unit, we know we’re always going to score goals. When the pressure is on us everyone steps up."
Walcott also spoke fondly of both his early goal and Arsenal's stoic defence, while he also acknowledged QPR's valiant efforts to put the Gunners under pressure.
"It was a well worked goal. It’s always nice to get an early goal and settle the nerves," he continued.
"QPR deserve credit because they put us under a bit of pressure but our defence has been solid for the last few months now."