Sciver took three wickets and scored 63 runs in the chase. Opener Tammy Beaumont was England's top run scorer with an unbeaten 72.
England women secured an unassailable 2-0 win over New Zealand with a seven-wicket win in the second ODI on Friday. Natalie Sciver led the way with bat and ball as England dismissed New Zealand for 192 runs and then chased down the target in 37.4 overs.
Sciver took three wickets and scored 63 runs in the chase. Opener Tammy Beaumont was England's top run scorer with an unbeaten 72 while wicketkeeper-batter Amy Jones scored an unbeaten 46.
Brooke Halliday anchored the faltering New Zealand innings with her second half-century of the series. She fell to Sciver on 60 and the second-highest scorer for the hosts after Halliday was number nine Hannah Rowe with an unbeaten 29.
England had earlier won the first ODI by eight wickets. The series is being played at the University Oval in Dunedin and the third and final ODI will be played on Sunday.
Brief scores: New Zealand Women 192 in 49.5 overs (Brooke Halliday 60, Hannah Rowe 29 not out; Natalie Sciver 3-26, Katherine Brunt 2-34) lost to England Women 194/3 in 37.4 overs (Tammy Beaumont 72 not out, Natalie Sciver 63, Amy Jones 46 not out; Brooke Halliday 1-18) by seven wickets with 74 balls remaining.
