United ended a run of eight games without a win as second half goals from Anthony Martial and Wayne Rooney sealed victory over Swansea at Old Trafford.
The Swans had won all three of their league meetings against United with Louis van Gaal in charge and history seemed dangerously close to repeating after Gylfi Sigurdsson cancelled out Martial's opener.
The Reds were not to be denied this time though and Rooney popped up 13 minutes from time to flick in an instinctive winner and get the Reds off to a victorious start in 2016.
The Reds started brightly and went close in the opening minute through Ander Herrera, whom had a shot blocked inside the box after an incisive one-two with Juan Mata.
Rooney fired into the side netting before Swansea's first opening fell to Wayne Routledge whom forced a smart save from David De Gea.
The Spaniard's opposite number Lukasz Fabianski soon found himself in the thick of the action before the break, when he twice denied Mata and then kept out Rooney from Ashley Young's excellent cross.
Having gone in at half-time goalless yet again, the hosts took the lead two minutes after the restart.
The goal came after excellent link-up between United's two most impressive performers on the day as Young picked out Martial for the Frenchman to steer home his eighth goal of the season with a header.
Swansea soon showed why they have become our bogey side, though, and went close through Andre Ayew's header against the post.
That chance lifted the visitors and their curse seemingly struck again on 70 minutes when substitute Modou Barrow crossed for Sigurdsson to loop his header beyond the despairing De Gea.
Old Trafford was stunned but United were not deterred and immediately pushed for a winner which duly arrived 13 minutes from time.
Martial skipped past Federico Fernandez on the left and crossed for Rooney to flick home a clever finish and restore his side's slender advantage.
Back came Swansea, though and, after Barrow was foiled by De Gea, United were forced to survive two huge scares in the dying minutes.
First, De Gea made a superb flying save from Ashley Williams' deflected shot, before Swansea sent Fabianski forward and he headed inches wide with the final action of the match.
Overall team performance: 7/10
United Faithful Man of the Match: Ashley Young