Sylvain Wiltord's 24th-minute winner ended Arsenal's run of three home defeats and lifted them to within one point of leaders Liverpool.
Wiltord sidefooted in Oleg Luzhny's low centre after a run by Thierry Henry, while Newcastle, playing their third game in five days, looked a spent force in a quiet second half.
Sir Bobby Robson's side survived an early scare when Dennis Bergkamp hit a 20-yard curler against a post and Shay Given held his second attempt.
Patrick Vieira headed inches wide from a corner a few minutes before Wiltord struck.
Freddie Ljungberg was the width of the bar away from adding Arsenal's second when his 31st-minute lob beat Given but bounced off the bar.
The Newcastle keeper also denied Ljungberg from close range as the half closed.
Midfielder Hugo Viana fired Newcastle's best effort, a thumping 30-yard shot that crashed off the underside of the bar seven minutes before the interval.
The highlight of the second period was a lively 20-minute substitute appearance by Robert Pires. First he split the Newcastle defence to set up Henry who dragged his shot wide. Then the Footballer of the Year shot narrowly over from Wiltord's pass.
Arsenal have now won their last two Premiership games after their blip last month. Newcastle slipped to ninth in the table after their defeat.