How's 138-ball innings included 27 boundaries and eight sixes on the small Seddon Park ground and surpassed the 170 that New Zealand captain Brendon McCullum scored for Otago against Auckland in March, 2008.
It is the second-equal highest List A - or domestic one-day - score in world cricket. Ali Brown made 268 for Surrey against Glamorgan at The Oval in 2002, while South Africa's Graeme Pollock scored 222 not out for Eastern Province against Border in October 1974.
India's Virender Sehwag holds the highest one-day international record, with his 2011 innings of 219 against West Indies in Indore.
How survived two chances, the first when he was bowled from a no-ball by Anurag Verma on 76 and again when Jono Hickey dropped a catch when he neared 150. He was eventually dismissed when caught by Anton Devcich off Brent Arnel's bowling.
How's 321-run partnership with fellow opener Jeet Reval (115) was also the highest for any wicket in a New Zealand List A fixture, surpassing the 273 set by Wellington's Michael Papps and Stephen Murdoch last week.
The previous highest opening partnership was 205, set by Wellington's John Aiken and Mark Douglas in the 1994/95 season.