Rosemary Mair then dismissed Lewis before Bates rounded off the win to deny Ireland.
“It has been a disappointing start to the tournament, so today was just about body language and turning up,” Kerr told Sky Sport after the match. “We need to turn up and believe we can still win games of cricket.
“I don’t necessarily think a couple of training sessions will change anything. We’re a good side — it is just about holding our nerve when the game is on the line, and in the first two games we didn’t quite do that.”
After being sent in to bat, New Zealand got off to a horror start, with Izzy Gaze, Georgia Plimmer and Maddy Green all dismissed inside the opening three overs to leave the Ferns reeling at 10-3.
Kerr (30 from 24) helped get New Zealand back on track before Brooke Halliday (34 from 37) and Izzy Sharp (36 from 28) combined to put the Ferns in a strong position.
Bates came in to close out the innings with a quick-fire 19 to help New Zealand reach 140-6.
Suzie Bates. Photo / Photosport
In reply, Ireland lost Amy Hunter early before Lewis and Prendergast put on a 110-run second-wicket stand to steer them to 116-1, before two wickets in three balls from Kerr all but ended their hopes.
“It’s hard to reflect straight away. There’s a lot of emotion. We wanted that first win so badly,” Lewis said.
“As a team, we did so much right. It’s hard to sum up right now.”
The White Ferns are back in action on Tuesday, when they face Scotland in Bristol. They must win that match and their final pool game against England, and have other results go their way, to have a chance of making the semi-finals.
Ben Francis is an Auckland-based reporter for the New Zealand Herald who covers breaking sports news.