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The Gunners had picked up just one point from their previous two Premier League games against Everton and Fulham before they suffered a 2-1 defeat to Villarreal in the first leg of their Europa League semi-final on Friday (AEST). 

However, they sealed all three points at St James' Park thanks to Elneny's early goal and Aubameyang's second-half finish, the fifth consecutive game in which the Gabon international has scored against the Magpies. 

The result lifted Arsenal up to ninth, while Newcastle finished with 10 men after substitute Fabian Schar's rash lunge on fellow Gabriel Martinelli.

Steve Bruce's side remains 17th, nine points clear of the relegation zone with four games remaining.

Arsenal wasted little time stamping their authority on the game, opening the scoring after just five minutes through Elneny's first Premier League goal in his 66th appearance in the competition.

Aubameyang horribly miss-kicked Hector Bellerin's right-wing cross but the ball fell fortuitously to Elneny, who struck a half-volley past Martin Dubravka from 18 yards.

Mat Ryan – one of nine changes from the defeat to Villarreal – tipped over Allan Saint-Maximin's deflected effort soon after, while Dubravka pawed away Granit Xhaka's long-range drive at the other end.

Miguel Almiron denied Elneny a second shortly before the half-hour, clearing the Egyptian's header from a corner off the line.

Arsenal doubled its advantage in the 66th minute when Aubameyang showed superb athleticism to volley home Martinelli's left-wing cross inside the six-yard box. 

Any faint hopes the hosts had of setting up a grandstand finale were dashed in the 90th minute when Schar saw red, as Bruce's men fell to just a second defeat in their past nine Premier League games.