Alex Ferguson’s side regained top spot from neighbours Manchester City, moving three points clear in the process, but, once again, they had to do it the hard way.
The Red Devils have now come from behind to win seven times this season. They completed the task here in dramatic fashion after squeezing home following seven first-half goals.
The visitors fell behind to Hal Robson-Kanu’s opener before Anderson and Wayne Rooney’s penalty looked to have put them in control.
But two headers from Adam Le Fondre and Sean Morrison, both from identical corners, would have left Ferguson at his wits’ end.
United responded through Rooney before van Persie wrapped up the win, but they will know they cannot afford to keep being so charitable if they want to regain the title.