United overcame the Conference side in difficult blustery conditions. An early Cristiano Ronaldo goal set them on their way but it wasn't until the last couple of minutes, when Wayne Rooney made it 2-0, that the Premiership side finally saw off the South Devon side.
Boro will travel to Old Trafford for the 4th round tie on Saturday 29th January. The game is been shown live on BBC1 with a 5.20pm kick-off.