The fan grabbed the referee around the neck, dragging him to the ground. But police were quickly on the scene and led the man off the pitch.
Wigan retained their position at the top of the Second Division despite conceding a late equaliser at home to Cambridge. The Lancashire side went ahead through their former Manchester United trainee, Pat McGibbon, three minutes into the second half. Cambridge, however, fought back well and John Taylor equalised in the 77th minute.
Burnley could not take advantage of their local rivals' slip, falling to their first defeat of the season at Bristol Rovers. Jamie Cureton's 37th-minute penalty proved decisive.
Ian Lawson hit a hat-trick as Bury coasted to a 5-2 win over Colchester. Adrian Littlejohn and Andy Preece were Bury's other scorers, with Colchester replying through Richard Wilkins and Lomano Lua-Lua.
Guy Ipoua put Scunthorpe ahead against Cardiff at Ninian Park before Jamie Hughes' late goal rescued a point for the Welsh club.