Ashley Young capitalised on a late error from Newcastle keeper Tim Krul to give the Reds a vital victory on Tyneside.
Despite a dominant performance (our best of the season in my view), the Reds were continually frustrated by a string of top drawer saves from the Dutch keeper so it was ironic therefore, that it was his mistake that gifted the Reds victory.
It looked as though the visitors had dropped two crucial points when Krul, under pressure from Wayne Rooney, hacked a loose Newcastle backpass straight to Young who gobbled up the chance from close range to seal a hugely important victory.
The Reds survived an early appeal for a Newcastle penalty, when Emmanuel Riviere went down under a challenge from Chris Smalling, but replays showed that contact was minimal.
Ander Herrera flashed an effort narrowly wide after good link-up play from Marcos Rojo and Rooney, before the skipper dragged his low effort wide after Young and the improved Angel Di Maria had combined well.
A minute before the break, Krul reacted superbly to claw away a Marouane Fellaini header, whilst his opposite number was called into action to deny Riviere.
The French forward had another close-range effort blocked by De Gea shortly after the interval before Krul made a fantastic double save soon after.
Fellaini found himself clean through but the Dutchman reacted superbly to block the Belgian's effort and then recovered excellently to keep out Young's angled drive on the follow-up.
Rooney had a goal chalked out for offside, but, with United having failed to put their opponents away, Newcastle squandered a golden opportunity to take a 75th minute lead.
Substitute Ayoze Perez dispossessed Herrera and put Papiss Cisse clean through, but the Magpies leading scorer fired wastefully wide and the chance was gone.
The home side were buoyed by the heart-warming return of Jonas Gutierrez after 17 months following a battle with cancer, but it was the Reds who struck late to earn three precious points.
Even then, though, the Magpies did not go quietly and almost salvaged a point with the last action of the game when Cisse's bullet header from point blank range was clawed away by De Gea, but the Reds held out.
United Faithful Man of the Match: Ashley Young
Overall team performance: 8/10