New Zealand was let down by 17 wides and 27 extras in total while five of the six White Ferns bowlers conceded at least one six off their bowling.
The White Ferns never looked a chance in the chase with a slow start exacerbated by the departure of Suzie Bates for six in the seventh over ending a rare out of form series for the New Zealand opener who had a high score of 28 in the five matches.
By the 18th over the White Ferns were 66 for five - still 282 shy of the target - with Amy Satterthwaite (six) and captain Sophie Devine (three) also back in the pavilion for single figures.
Lauren Down (27) and Brooke Halliday (27) top-scored for the White Ferns in a tame chase that ended in the 36th over.
Knight, who was named player of the series, finished with 3-24 late in the innings for the hosts though what the scorebook won't show is that two of her wickets came from a long-hop and a full-toss.
It's not all doom and gloom for the White Ferns who head into this summer's home World Cup having won just two of their 17 games since the start of 2020. They pushed England in the opening four games in the series and could have been playing a decider.
"One of those games you flush down the dunny," Devine said after the loss. "We could have gone into this game 4-0 up. Serious competition for places, will hold us in good stead going into the World Cup."