Mesut Ozil scored his third goal of the season with a superb volley
Newcastle dropped into the relegation zone after suffering a fourth defeat in a row, while Arsenal moved back into the top four with a narrow victory.
Mesut Ozil's brilliant volleyed goal in the first half was enough for Arsene Wenger's side, who dominated until a late rally from Newcastle.
Ainsley Maitland-Niles hit the side-netting for Arsenal before the break, but Newcastle had chances in the second half for Jacob Murphy and Ayoze Perez.
The result puts Arsenal into fourth place while Newcastle have now claimed just one point from the last 27.
Newcastle only came to life in the latter stages, with Perez failing to take advantage of two rare chances when he put a shot and then a header over the bar.
Arsenal 1-0 Newcastle:Mesut Ozil's goal was a gem - Arsene Wenger
Jack Wilshere came the closest to giving Arsenal breathing space late on when he saw his side-footed shot saved by the recalled Rob Elliot in the Newcastle goal.
It was Newcastle's 10th straight Premier League defeat to Arsenal and they are now without a league win since 21 October when they beat Crystal Palace 1-0.
Edgy Arsenal relieved by Ozil brilliance
Seventh in the table at kick-off and without a win in three matches is not the sort of run-in to the busy festive schedule that Arsenal are accustomed to.
And hamstring and groin injuries to Aaron Ramsey and Theo Walcott respectively also gave Wenger much to ponder in the lead-up to the meeting with Newcastle.
As this touch map shows, Mesut Ozil only featured in the final two-thirds of the pitch in his excellent display against Newcastle
They looked slick for much of the afternoon and threatened around the edge of Newcastle's area on a regular basis, but the lack of the killer instinct in front of goal led to some edginess as the match wore on.
Ozil's moment of magic was the one real ray of light on a grey afternoon, the Germany international showing impeccable technique and balance to strike the ball beyond a helpless Elliot after Newcastle failed to clear.
With Liverpool the next league visitors to the Emirates, Arsenal will be thankful for the split second of brilliance that helped to end a worrying dip in results.
Newcastle's slide continues
When Newcastle captain Jamaal Lascelles forced Petr Cech into a save when he rose unmarked to head a free-kick on target early on, Rafael Benitez must have hoped it was a sign of things to come.
Newcastle striker Joselu made no touches inside the Arsenal area
But Newcastle retreated into their shells for much of the match, and struggled to chase the game after falling behind.
Their slide down the table, from sixth when they beat Palace for their last victory on 21 October, has coincided with stories of a potential takeover by PCP Partners said to be in the region of £300m.
Magpies fans will want matters resolving soon, as their side looks to be in dire need of an injection of fresh talent in the forthcoming transfer window to spark them back to life.
Man of the match - Mesut Ozil (Arsenal)
Mesut Ozil was integral to Arsenal's win, with 123 touches and just under 90% of his 106 passes finding their target, as well as his brilliant winner
"We need something in January" - what they said
Newcastle manager Rafael Benitez: "We had our chances.We were pushing and attacking.We had chances to draw.It's a pity.We are learning.In some games we are one goal behind.The players are working hard.It's a pity.
"We need to be competitive like today and keep going.We are a young team.When you're not winning you lose confidence.We have to keep working this way.Try to get a result.In January, try to bring in people.
Arsenal 1-0 Newcastle:We need players in January - Rafael Benitez
"The fans know the team will be tough.They also know we need something in January - that will help the current squad."
Arsenal manager Arsene Wenger: "The necessity to win was playing on the mind of the players towards the end.
"We had three games in six days.In the last one you could suffer because Newcastle produced a physical performance.
"We had two away games and two draws.Against Manchester United we had a quality performance but couldn't get the win."
Home is where the heart is for Arsenal - the stats you may have missed
- Arsenal have won 13 of their last 14 home Premier League games, losing the other to Manchester United.
- Newcastle are without a win in nine Premier League games (D1 L8), their longest winless run in league football since May 2015 (10).
- Rafa Benitez has never enjoyed a victory away to Arsenal in the Premier League in seven attempts, drawing two and losing five.
- Jack Wilshere started consecutive Premier League games for Arsenal for the first time since May 2015.
- Mesut Ozil has been directly involved in six goals in his last five Premier League games at the Emirates (two goals, four assists).
- Ozil has had a hand in three goals in his three top-flight appearances against Newcastle (2 goals, 1 assist).
- The German created eight goal-scoring chances - only Kevin de Bruyne (nine v Southampton in November) has managed more in a single Premier League game this season.Ozil also managed eight v Everton in October.
- Petr Cech has now kept 199 Premier League clean sheets.
Arsenal face West Ham for the second time inside a week when they host the Carabao Cup quarter-final at 19:45 GMT on Tuesday, 19 December.The Gunners then host Liverpool at the Emirates Stadium in the Premier League on Friday, 22 December at 19:45.
Newcastle are back in London for their next outing, away to West Ham on Saturday, 23 December at 15:00 GMT....