Story of the match
It was a good night all round for Aubameyang, the former Borussia Dortmund striker - who had earlier thudded the woodwork in the first half - after he opened the scoring five minutes after the break to make it 1-0, when he beat Newcastle goalkeeper Karl Darlow.
The home side ramped up the pressure on the beleaguered boss of the visitors Steve Bruce when they doubled their lead as Emile Smith-Rowe's pullback found Bukayo Saka and the teenage England international side-footed the ball into the net.
Aubaymeyang notched his second and the Gunners' third after Cedric Soares - starting his first league game of the season, raced to the byline to feed the Gabon international.
Another player who caught the eye for Arsenal was Thomas Partey who impressed in the heart of battle with defensive discipline, intelligent positioning and a willing to receive the ball in tight corners, while happily prompting attacks for colleagues further forward - not to mention an assist for Aubameyang's opener.
Miguel Almiron had Newcastle's best chance but shot over from the edge of the penalty area at 0-0.
Newcastle are 15th, seven points clear of 18th-placed Fulham, albeit with the west Londoners having a game in hand.
With Bruce facing renewed calls for his sacking following on from the dire 1-0 loss to bottom-of-the-table Sheffield United last week, his side have now not won in nine matches in all competitions.
After dispatching Newcastle for the second time in nine days, Arteta's side await the winners of the delayed Shrewsbury vs Southampton FA Cup match before they find out who they will face in the fourth round on Saturday lunchtime.
For Bruce's Newcastle, after another miserable defeat in north London the season just got tougher.