Second-half goals from Juan Mata and Marouane Fellaini were enough to seal victory on a night that saw United dominate ball possession and shot count, after Hull had held firm for almost an hour.
It was all United from the get-go, with Mata, Henrikh Mkhitaryan and Marcus Rashford all seeing plenty of the ball, while the trio also squandered a number of half-chances.
The visiting Tigers almost took a shock lead through Adama Diomande, who headed onto the post on the half-hour mark, before being ruled offside by the linesman.
Jose Mourinho’s side, who have now won nine successive games in all competitions, were quick out of the blocks at the restart, too, with Mkhitaryan continuing to pull the strings.
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The Armenian then had a hand in breaking the deadlock - his header towards the back post was latched onto by Mata, as Old Trafford finally had something to celebrate.
Returning to the KCOM Stadium at the end of the month with just a one-goal deficit to overturn would have been considered a good result for Hull, but Fellaini’s header from Matteo Darmian’s cross put paid to those hopes on 87 minutes.
United have now won 12 of their last 13 games against their East Yorkshire opponents, meaning Marco Silva's men have it all to do if they are to reach their maiden EFL Cup Final at the home of football in February.