The Gunners seem to have problem winning at home following their 0-0 draw with Liverpool on Monday, but their good away form continued at Saint James Park.
Despite doubt over his back injury, Laurent Koscielny was back for Arsenal but influential midfielder, Mesut Ozil was missing with a minor knee injury.
Arsenal settled into the game early in the first half, keeping much of the ball as they look for spaces behind the defence to playing in Theo Walcott who replaced Olivier Giroud in the starting line-up.
They had the advantage after the sending off of summer signingAleksandr Mitrovic, who got a straight red card for a studs-up challenge in the 16th minute on Francis Coquelin.
Newcastle, winless in their first four Premier League matches had no choice than to defend against an Arsenal side who already with the advantage will keep much of the ball and press.
Steve McClaren‘s side stay resolute in the first half despite being one man down as Arsenal had only one shot in target at the end of the first half.
Arsenal’s goal 20 minutes in to the second half.