Dartford lost 2-1 at home to Luton to keep the Bulls a point clear of the bottom four. The Darts held the lead, dropping the Bulls into trouble, but a red card and two Luton goals swung the game late on.
Southport remain three points ahead of the Bulls after losing 4-0 at home to Braintree. Woking racked up their fifth straight win with a 2-1 victory over Forest Green.
Cambridge cemented second place with a 1-0 win over Macclesfield, while Grimsby beat Wrexham 1-0 to leave the Dragons with just one point from nine under Kevin Wilkin.