Agriculture recovered in the March 2018 quarter, up 0.4 per cent, following a 2.8 per cent fall last quarter.
A rebound in milk production contributed the most to the rise, largely due to improved weather conditions, after hot, dry weather in the December 2017 quarter.
However, construction cooled off, down 1 per cent in the quarter but still up 1.4 per cent for the year.
Westpac economists said the result was slightly stronger than they had predicted.
"Growth was a little more widespread than we expected," said senior economist Michael Gordon.
"The main surprise for us was a 2.3 per cent rise in the information and telecommunications sector."
Gordon noted that the New Zealand economy had lost some momentum in the past year, with growth in the last three quarters matching or barely exceeding population growth.
"However, increased fiscal spending should provide a boost to activity from the second half of this year onwards," he said.
GDP per capita was flat this quarter, following a 0.1 per cent increase in the December 2017 quarter.
The size of the economy in current prices was $286 billion.
There was no market reaction to the release. The New Zealand dollar recently traded at 68.59 US cents, and was little changed.