Anna O'Flanagan and Katie Mullan scored as Ireland beat 2016 Olympic bronze medallists Germany 2-1 in their opening game of the Berlin Four Nations Cup.
O'Flanagan put Ireland ahead but Germany equalised in the third quarter.
Mullan scored the winner by diverting in a long ball from Hannah Matthews in the final quarter and Ireland now face China on Friday and Korea on Sunday.
Ireland will next meet Germany in the pool stages of this year's World League semi-finals in Johannesburg in July.
The World League 3 tournament in South Africa will be followed by the Eurohockey Championships in August.