Import seamer Chris Tremain claimed an economical 2-21 from four overs for Northern Districts and veteran Graeme Aldridge also clocked in with 2-26 from three overs.
ND's win meant they have now picked up the spoils in four of their five matches and sit atop the table on 16 points, while CD are at the bottom without a win from four games.
Otago, who are in second on 14 points, have Northern Districts in their sights though as they registered their third win in five contests when breezing past Auckland by eight wickets in Alexandra.
Set only 120 to win, the home side crushed Auckland's bowling attack to romp home in the 16th over with Neil Broom top-scoring with 51, while fellow opener Hamish Rutherford added 49 from 42 balls. Their first-wicket garnered 99 from 12.3 overs.
Auckland's total of 119-9 was always unlikely to be enough and only Jeet Raval (56) made a splash with the bat as Otago seamer James McMillan proved tough to get away as he took 2-8 from four overs.
Meanwhile, at the Basin Reserve in Wellington, poor weather washed out any chance of a ball being bowled between the third-placed Wellington and fifth-placed Canterbury.
It marked the third time in five outings Canterbury have been involved in an abandoned game.
