United were handed a flying start as the Magpies' makeshift defence crumbled horrifically on two occasions inside the opening 16 minutes to allow first Jonny Evans and then Patrice Evra to head home.
Tom Cleverley's 71st-minute strike from long range ensured the visitors avenged their 3-0 defeat at St James' Park last season in fine style.
Evans left both Mike Williamson and Demba Ba for dead to apply the finishing touch to Robin van Persie's right-wing delivery with eight minutes gone, and as many minutes later, Evra, hardly the most imposing of figures physically, was similarly unaccompanied as he reached Wayne Rooney's set-piece from the left with the same result.
Newcastle's defending was simply shambolic and while they could point to the absence of Tim Krul, Danny Simpson, Steven Taylor and Fabricio Coloccini, four certain starters in their first-choice back five, the men handed the marking jobs in their absence failed miserably in their tasks.
Gradually the Magpies worked their way into the game, Jonas Gutierrez dragging an 18th-minute shot just wide and Yohan Cabaye only just missing the target with a curling effort.
Ba turned a Papiss Cisse cross over the bar under pressure and Cisse headed wide from a Cabaye free-kick, but crucially, the Magpies failed to test goalkeeper David de Gea.
Newcastle thought they were back in it within five minutes of the restart when Ba got to Shane Ferguson's cross ahead of De Gea, but saw his effort come back off the bar. Cisse headed the rebound towards goal, where the keeper managed to divert it on to the post with the striker insisting the ball had already crossed the line, but to no avail.
Ba headed wide from another Cabaye cross, but United continued to threaten on the counter and might have extended their lead when Danny Welbeck held off Davide Santon and laid the ball off for Cleverley, but the midfielder skied his 57th-minute effort.
The home side kept plugging away with Hatem Ben Arfa dragging a well-struck left-foot shot marginally wide, but the game was over 19 minutes from time when Cleverley accepted Rooney's lay-off on the left wing and curled the ball right-footed across Steve Harper and into the top corner.