Casemiro’s bullet header opened the scoring midway through the first half before Marcus Rashford’s effort took a deflection off of Newcastle defender Sven Botman to double the lead, going down as own goal by the Magpies man.
Newcastle did test David De Gea’s goal during the second half, but after defending stoutly, the Reds managed to claim victory in London and would have extended the lead but for Loris Karius's heroics.
Erik ten Hag has now picked up his first piece of silverware as United manager, in his first season since joining from Ajax.
FIRST HALF - REDS AT THE DOUBLE
Both sides started with quick counter-attacks to try to catch the other team out.