The no-result at the Melbourne Cricket Ground left New Zealand top of Group 1 on three points, the Black Caps having beaten champions and hosts Australia in their Super 12 opener last Saturday.
Afghanistan, who lost to England in their first match, remain bottom of the group on one point.
Third-placed England earlier suffered a shock defeat to Ireland in the first match of the double-header at the MCG, with rain cutting the match short and leaving the English short of their par score calculated by the Duckworth-Lewis-Stern method.
Rain could yet influence the standings in Group 1, with a poor weather forecast on Friday in Melbourne where Australia play England after Ireland meet Afghanistan at the MCG.
New Zealand coach Gary Stead said Wednesday's washout made the Black Caps' first-up thrashing of hosts Australia all the more precious.
"I definitely think it helps," he told reporters.
"I think (Ireland's win) also shows there are no easy games right through the tournament either.
"So that's good for cricket. It does make our pool a little bit predictable."
