A goal just two minutes from fulltime has seen Japan snatch a 2-1 win over the Vantage Black Sticks Women at the Vantage Festival of Hockey.
In a rematch of last years final, Japan drew first blood when Motomi Kawamura slotted one from a penalty corner in the eighth minute.
Following the first half, which was disrupted for some time by a burst water main, the Japanese held their advantage deep into the fourth quarter.
The Black Sticks delivered an equalising blow in the 54th minute thanks to a low and strong penalty corner drag flick from Brooke Neal.
But Japan struck again with less than two minutes on the clock with a defensive error giving away another penalty corner opportunity and allowing Yu Asai to score the winning goal.
Black Sticks midfielder Pippa Hayward said it was a game which should have ended with a draw.
"Its quite a disappointing start to the tournament for us, we need to be a lot better and have work to do in both the attacking and defensive circles."
New Zealand will look to shake off their opening loss when they go up against trans-Tasman rivals Australia at 5pm tomorrow.
Earlier on opening day the Hockeyroos played out a 1-1 draw with USA, with captain Alyssa Parker scoring for the United States before Madi Ratcliffe equalised for Australia early in the second half.
VANTAGE BLACK STICKS WOMEN 1: (Brooke Neal)
JAPAN 2: (Motomi Kawamura, Yu Asai)
Halftime: Japan 1-0