On a baking hot day, Munro was not the only batsman to fry the bowlers.
But the punishing left-hander has a reputation as one of the most destructive players on the domestic scene and lived up to his billing, posting 100 from just 69 deliveries.
It was the sixth-fastest one-day hundred scored in New Zealand and helped his side overhaul the Volts' total of 313 for eight.
Eventually, Munro found a fielder in the deep and was caught out for 110 (from 79 deliveries), having whacked five sixes and 10 fours.
Earlier, he had combined in a destructive partnership with rookie Glenn Phillips.
The pair put on 121 at better than a run a ball to get their side into a dominant position despite chasing a mammoth score.
Phillips, who turned 19 earlier this month and was playing in just his third one-dayer, looked every bit at home at the top level on his way to a maiden century.
The South African-born right-hander was quick to swivel into pull shots and anything overtossed was lofted down the ground on his way to a sparkling 101.
And spare a thought for Otago's Neil Broom. He also played a blinder, scoring his fifth one-day 100. He was undone on 101 from 99 balls and his superb knock formed the spine of Otago's innings.
On a day when the bowlers spent a lot of time with their hands on their hips watching the ball sail to the boundary, Auckland's Lockie Ferguson was one of the few who could walk away feeling content.
He took four for 68 and three of his wickets were the key scalps of Broom, Michael Bracewell and Hamish Rutherford. It was his one-day debut as well.
Volts coach Nathan King said the partnership between Munro and Phillips took the game away from his side.
‘‘It was pretty defining period of the game,'' he said.
‘‘They both batted really well and got their team into a good position.
‘‘The wicket played a little bit better than what we thought, so that is a credit to the ground staff. But the nature of one-day cricket now is you can score 300 and you still don't feel safe.
‘‘We didn't feel at halftime we had it in the bag. We knew we'd have to bowl and field well. That is just the way one-day cricket in going now.''
Otago lost some momentum when Broom was closing in on a hundred and while Derek de Boorder was getting established.
But other than that brief patch towards the end of the innings, the Volts batted as well as could be expected.
When Munro holed out, the Volts came back into contention. The visiting side still needed more than 50 runs and there was a late flurry of wickets.
But Tarun Nethula remained calm and added an undefeated 16 from 12 to help seal the win.
In Napier, Canterbury beat Central Districts by six wickets, overhauling a modest 167 with more than eight overs to spare.
At the Basin Reserve, Wellington chased down Northern Districts total of 267 for nine to win by five wickets.
