Japan claimed a fine 2-1 victory over Commonwealth champions New Zealand to blow Pool D wide open at the Women's Hockey World Cup in London.
The Kiwis were looking to build on their opening success over Belgium at the Lee Valley Hockey and Tennis Centre while the Japanese needed to bounce back from defeat to Australia in their first match.
Despite being ranked 12th compared to New Zealand's fourth, the Asian nation adapted best to sweltering conditions and built a two goal lead after the break.
Oikwawa Shihori first blasted home from a penalty corner and Minami Shimizu doubled the advantage after rounding Sally Rutherford and slotting home.
Anita McLaren brought the Gold Coast 2018 winners back into contention after scoring from a penalty stroke but Japan held on.
It leaves the group beautifully poised with one match each to play as Australia, the runners-up at the last World Cup in 2014 and three-time Olympic champions, could only draw 0-0 with the Belgians.
Two games will be played tomorrow with hosts England meeting United States in Pool B.
Germany and Argentina will also meet in Pool C.
All of the four group winners will automatically enter the quarter-finals with teams in second and third facing play-off matches.