Dereham lost 1-0 at home to Setch's Corby, with the only goal of the match coming from ex Linnet Toby Hilliard.
Fakenham also lost 1-0 at home, to Harleston.
Swaffham drew 3-3 at home to Diss.
Downham won 4-0 away to Norwich CBS, moving to 2nd in the table behind Heacham.
Heacham won 3-0 at home to Whittlesey, taking them two points clear at the top of the table.