Arsenal went ahead on five minutes when the Gabonese striker mishit his shot and the ball fell invitingly for Mohamed Elneny, who fired in his first PL goal.
Grant Xhaka’s 29th-minute shot was tipped over by Martin Dubravka before Elneny’s header was cleared off the line by Miguel Almiron from the resulting corner.
The Gunners’ pressure was rewarded on 66 minutes when Aubameyang acrobatically volleyed in a brilliant left-wing delivery from Gabriel Martinelli, meaning he has scored in five successive league matches versus Newcastle.
Fabian Schar was sent off for a challenge on Martinelli late on as Arsenal moved up to ninth in the table on 49 points, five adrift of the top six.
Newcastle remain 17th, nine points clear of the relegation zone with four matches remaining.
Newcastle: 7 May v Leicester (A)
Arsenal: 9 May v West Brom (H)
Referee: Mike Dean. Assistants: Ian Hussin, Dan Robathan. Fourth official: Andy Madley. VAR: Chris Kavanagh. Assistant VAR: Matthew Wilkes.
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