The Volts have won their last six games on the trot and made no contest of their clash with the struggling Central.
Otago's impressive top order delivered with Black Caps' all-rounder Nathan McCullum (50) and Dutch international Ryan ten Doeschate whacking half centuries to help the Volts post an imposing 194 for four.
The visitors could manage only 101 in reply and are anchored at the foot of the competition table with four points from seven games. Otago are on top with 24 points and, with three round-robin games remaining, the side have given themselves an excellent chance of hosting the final.
Ten Doeschate has been a revelation for Otago this summer. Two seasons ago he was outstanding for Canterbury and has been even more consistent this season with scores of 65, 60no, 47, 61, 26 and 59no today.
He brought up his 50 with a massive six on to the roof of the grandstand and has now scored 318 runs in six games at an average of a shade under 80.
Everyone got in the wickets for Otago, but left arm spinner Nick Beard was the pick with two for 10 from three overs, and McCullum took two for 21 from four overs.
Central had some bad luck with batsman William Young forced to pull out through injury. That left the visitors forced to play Adam Milne, who did not bowl because of an ankle injury.