The Black Sticks Women have come away with a gutsy 3-2 win over the United States thanks to goals from Kayla Sharland, Gemma Flynn and Clarissa Eshuis.
It was the win they needed to keep their Olympic semi-final hopes alive.
But there is still some way to go.
The young New Zealand side now need to win against Germany on Monday to book a spot in the medal rounds.
A draw could get them through, but they would be reliant on the results of other Pool B games going their way.
"We have got a big hill to climb. We will have to perform above ourselves if we are to beat them [Germany] in the next game. But I think it is a challenge this team is ready for and hopefully we can achieve that," said head coach Hager.
"The United States are a tough team, we always knew that they would counter attack and create opportunities, they made it hard for us as they have with every team here. We are just pleased to come away with a win."
Co-captain Emily Naylor returned to the turf tonight after a back niggle took her out of the last game against Argentina.
It was a big night for Naylor, playing her 200th test match while Capital's Anita Punt got her 100th cap.
An early goal is becoming a Black Sticks trade mark in this Olympic tournament.
This time it was co-captain Kayla Sharland who scored in the second minute from a penalty corner drag flick.
American Katie O'Donnell equalised in the 16th minute, but New Zealand snatched the lead back three minutes later when Gemma Flynn found the back of the net at the break down of a penalty corner.
Claire Laubach was USA's answer when she converted a penalty corner and equalised in the 34th minute.
The start of the second half was much more settled than the first, with the Black Sticks unable to capitalise on the ball that they worked tirelessly to turn over.
There was a dramatic moment when Stacey Michelsen was standing at the post and deflected the ball in, but the goal was disallowed by the video umpire due to her high stick.
With 20 shots on goal compared with USA's two goals from only two attempts throughout the game, it was an Eshuis drag flick that saw the ball rocket to the back of the net and put the Kiwis 3-2 up with six minutes left on the clock.
The pressure mounted for the Kiwis when Michelsen was yellow carded for the second time in the game - this time it was later in the second half when the USA had pulled goal keeper Amy Swensen into the field of play.
The USA did all they could to equalise in the dying minutes, but the Black Sticks left the field with the win, even if it was by a smaller margin than they had perhaps hoped for.
The Black Sticks Women play their final pool game against Germany at 7.30pm on Monday (NZT).
New Zealand 3 (Kayla Sharland, Gemma Flynn, Clarissa Eshuis) United States (Katie O'Donnell, Claire Laubach) 2. HT: 2-2