Chasing seven runs per over, New Zealand openers were kept quiet by Anya Shrubsole and Natalie Sciver, who gave away just 15 runs in the first five overs. Down picked up a couple of boundaries to get the innings going, but it did not last long as Suzie Bates miscued Shrubsole to Beaumont at backward point.
Down got out shortly after to Sophie Ecclestone as the left-arm spinner deceived the White Ferns opener with a slower delivery and bowled her for 27 runs from 43 balls. Maddy Green, joined by Amy Satterthwaite, then tried to build a partnership.
The duo added 21 runs together before Ecclestone got her second as Green hit one back to the spinner. Kate Cross dismissed Satterthwaite in the very next over, reducing New Zealand to 63 for four. Cross got the big wicket of Sophie Devine, trapping her on the pads for just three runs from eight balls.
Katey Martin and Brooke Halliday tried to hit a few boundaries, but Cross struck again to clean up the former for five runs from nine balls. Hayley Jensen came out all guns blazing, smashing Ecclestone down the ground for a couple of boundaries.
She thumped Cross through the covers, and when Knight came on to bowl, Jensen smashed the England skipper down the ground. Knight had the last laugh as Jensen took a long walk back to the dressing room off the very next delivery.
After shining with the ball, Hannah Rowe tried to score runs with the bat alongside Halliday. They tried to build a partnership, but Knight got rid of both in the same over. New Zealand were eventually all out for 144, falling short by 203 runs.
After being put in to bat by New Zealand, Beaumont and Lauren Winfield-Hill started well for England. The duo had their share of luck, with Down dropping catches for both off Devine's bowling at backward-point. They survived through early nervy moments and picked up some critical boundaries.
Whenever the seamers pitched the ball short, England openers either freed their arms to smash it through the off-side or pulled with authority in the leg-side for a boundary. Beaumont started to accelerate by the end of the power play, hitting Molly Penfold for back-to-back boundaries. Winfield-Hill, too, joined the party as she crunched Jensen through the covers.
Together, they added 97 runs for the first wicket before Satterthwaite held on to a catch at mid-wicket to dismiss Winfield-Hill for 43 runs from 57 balls. Knight, the centurion from the previous match, was sent back to the pavilion in the very next over by Lea Tahuhu for a two-ball duck.
However, Beaumont, along with Sciver, made sure that the momentum did not drop. Sciver, in particular, farmed most of the strike early in the partnership, picking up some easy boundaries. She took the attack to Jensen, hitting boundaries off the back-foot. Beaumont eventually brought up her half-century, clobbering Devine between mid-on and mid-wicket.
Brought in to break the partnership, Rowe delivered with the wicket of Sciver against the run of play. Amy Jones, who had a quiet series till then, launched a counterattack. She smashed three boundaries off Rowe in one over and followed it up with another off Molly Penfold. When Satterthwaite came on to bowl, Jones lofted her for a massive six over deep extra-cover. The wicketkeeper-batter raced to her fifty in just 32 balls with a square-cut off Satterthwaite.
At the other end, Beaumont hit 13 runs in a Tahuhu over, closing in on her eighth ODI century. She brought up her first hundred against New Zealand in 110 balls. Soon, both Jones and Beaumont got out in quick succession. Having done well in the middle-order earlier in the series, Danielle Wyatt and Sophia Dunkley went berserk in the final overs.
Dunkley hit Devine for consecutive fours, while Wyatt swatted the New Zealand skipper over deep mid-wicket. In the last three overs, they smashed 44 runs, taking England to 347 for five in 50 overs. Wyatt scored 43 not out off just 20 balls, and Dunkley finished with an unbeaten 25-ball 33.
Brief Scores: England 347/5 in 50 overs (Tammy Beaumont 102, Amy Jones 60; Hannah Rowe 2/65) beat New Zealand 144/10 in 35.2 overs (Lauren Down 27, Brooke Halliday 27; Heather Knight 3/24) by 203 runs.