Argentina beat New Zealand 2-1 in the Olympic women's hockey match in London on Thursday. The half-time score was 1-0.
Carla Rebecchi scored both times, the first early in the game and the second 10 minutes into the second half.
However, with eight minutes to go, Charlotte Harris scored for New Zealand.
Argentina is the world number two and the Black Sticks don't have a good record against them.
Captain Kayla Sharland said earlier they were expecting a tough match.
The Blacks Sticks earlier beat Australia and South Africa to top their table with six points.
Three other teams are also on six points and the Black Sticks need to win their next game, against the United States on Saturdayday.
