Robin van Persie headed Manchester United to victory against old club Arsenal in a game that never truly sparked into life at Old Trafford.
The Dutchman's 27th minute header proved to be the difference between the two sides, as Wayne Rooney found his strike-partner in space in the box with a corner.
League leaders Arsenal were slow out of the traps, and failed to test David de Gea all afternoon despite getting into some decent positions - particularly in the second-half.
Van Persie's goal was the first real chance of note in the first period, before head injuries to Wojciech Szczesny and Nemanja Vidic slowed things down before the interval.
The Gunners were better after the break, but Aaron Ramsey and Mesut Ozil failed to test De Gea after some good build-up play. Olivier Giroud then spurned their best chance, firing wide from a difficult position.
At the other end, Rooney dragged a shot wide for Manchester United as they looked to double their advantage, and Chris Smalling failed to connect at the far post from close range.
Arsenal then began to dominate possession in the closing stages, but Arsene Wenger's side were unable to create a clear-cut chance to extend their lead at the top of the Premier League table.
The result means that David Moyes' side are now just five points behind the Gunners, who remain two points clear at the top of the table.