Head coach Mark Hager said it was an impressive result for his side, who had gained in confidence and momentum throughout the series.
"Argentina were a bit flat today, but full credit to our girls; we created a lot of opportunities and were able to put four of them away," he said.
"The first half was fairly even, and they put together a good period where we were under pressure but our defence I thought was very good and we controlled the second half.
"The result is pleasing for the group and it really highlights the work we are doing around building consistency. It's a pretty impressive effort to beat Argentina twice in a row, especially at home."
The Black Sticks now lead the six-test series with two wins, one loss and a draw with two games still to play.
Game five is at 11am this morning (NZT).
The Argentina series serves as an important part of the team's build-up to the Hawke's Bay Cup in April, the FIH Champions Trophy in June, and the Olympic Games in Rio de Janiero in August.
Black Sticks 4 (Stacey Michelsen, Brooke Neal, Petrea Webster, Gemma Flynn) Argentina 1 (Delfina Merino) Halftime: Black Sticks 1-0.