Sent in to bat, Canterbury posted 199 for 4 on the back of half-centuries from Tom Latham (63) and Henry Nicholls (67 not out), who was earlier in the day left out of New Zealand's ODI squad for the home series against Bangladesh.
Canterbury had lost Chad Bowes in the third over, but Peter Fulton helped get the innings going with a 34-ball 44 in which he struck six fours and a six. Then Latham and Nicholls built on the advantage.
Wellington were in control of the chase till the 12th over as they raced to 104 for 1, courtesy Hamish Marshall's sprightly half-century. But Todd Astle, the legspinner, struck to dismiss Marshall and break a 67-run second-wicket stand to revive Canterbury.
Then their bowlers applied the breaks, escalating the asking rate to ensure late cameos from Grant Elliott and Luke Ronchi weren't enough for Wellington, who succumbed to their third loss in the tournament to remain at the bottom of the points table.
Wellington had lost Michael Papps in the fifth over, before Marshall and Stephen Murdoch, who made a 29-ball 38, brought the equation down to 96 off 52 balls, with nine wickets in hand. But their dismissal in the space of 16 deliveries derailed the chase.
Astle finished with 2 for 36, while Kyle Jamieson and Ed Nuttall had one wicket apiece.
Mahela Jayawardene anchored Central Districts' innings before their bowlers took regular wickets to complete a five-run win against Otago in Napier. The win - their second in three games - saw Central Districts move to the top of the Super Smash table.
Choosing to bat, Central Districts opener George Walker fell for 15 after putting up a stand of 36 for the first wicket. His partner, Jayawardene then added 52 runs with Jesse Ryder (25) and another 25 runs with Will Young (18) to take the team to 113 before he was dismissed for 66 off 42 balls as the third wicket, by James Neesham. Tom Bruce remained not out as his 19-ball 33 took Central Districts to 166 for 5 while Neesham finished with figures of 4 for 24 from his four overs.
In their chase, Otago lost both openers Anaru Kitchen and Hamish Rutherford within their first three overs, the former being run out for 2. Michael Bracewell was the third to go with the team's score at 40 before Neil Broom, who was selected for New Zealand's ODI squad against Bangladesh, scored a 25-ball 28.
Broom was the fourth to go with the team at 57 for 4 before part-time spinner Walker struck to get rid of Derek de Boorder. With the team at 61 for 5, Neesham (34) added 51 runs for the sixth wicket with Josh Finnie (27) before they both fell in consecutive overs.
At seven-down, Brad Wilson hit a 10-ball 21, but with his dismissal at the beginning of the last over, Otago lost any hope of a win as they fell five runs short. By the end of the game, five Central Districts bowlers finished with wickets to their name.