United welcomed Southampton to Old Trafford having failed to pick up a win from their previous two top-flight fixtures, drawing 2-2 at Leicester City before labouring to the same result at home to Burnley on Boxing Day.
The hosts lost Romelu Lukaku to a head injury after only eight minutes and, with Zlatan Ibrahimovic omitted from the squad by Jose Mourinho, introduced Marcus Rashford to lead the line.
But United failed to cause goalkeeper Alex McCarthy – in for the dropped Fraser Forster – any real problems, although they did have a goal disallowed late on after an offside Paul Pogba got a touch to a Nemanja Matic effort that could have snuck inside the post without his intervention.
United could now start the new year 17 points adrift of City if their fierce rivals extend their winning run to 19 matches at Crystal Palace on Sunday.
DOWNLOAD MATCH HIGHLIGHTS