Pool D was blown wide open as yet another high ranked team fell to a tactically astute opponent.
New Zealand, who have enjoyed a rich vein of form in recent months would have been confident going into their second game of the Vitality Hockey Women's World Cup, but the Cherry Blossoms are a team that is in the ascendency.
Less of a shock, but still an upset was the 0-0 draw between Belgium and Australia. Goalless it might have been but this was an absorbing encounter between two teams who have been rebuilding their squad and their team culture.
"We have a training session called 'turnover Thursday, where we train under duress, this has really helped us to improve our thinking and decision making" Stephanie Vanden Borre, Belgium.
The opening match was played in extreme heat as temperatures in London rocketed to the mid-thirties and the temperature on the pitch was several degrees higher. New Zealand, who are currently fourth in the FIH Hero World Rankings have played Japan (WR:11) recently in the Pioneer Energy Tri Nations Women's International, beating the Cherry Blossoms twice, but this is a World Cup and nothing is a certainty.
While New Zealand had secured three points after a tough game with Belgium, Japan had been on the wrong side of a 3-2 loss to Australia. In that game, Japan had started slowly and turned a potentially clear-cut loss into a much closer affair with two quick goals in the final minutes of the game.
So the two questions ahead of the game was whether New Zealand had recovered from their exertions and whether Japan would pick up the momentum they had developed over the course of their opening match?
The first half was an open affair, with New Zealand playing their usual expansive and fast-running style of play and Japan looking for innovative passes that got their strikers in behind the Black Stick's defence. It was Japan who created the majority of chances in the first half.
The first of these came when Yu Asai found Motomi Kawamura in front of goal and unmarked. The striker just deflected the ball wide of Sally Rutherford in the New Zealand goal. Three penalty corners for the Cherry Blossoms also failed to provide a breakthrough but it was clear that Japan were paying no heed to the large disparity in world rankings.
As temperatures rose, so the players' fatigue levels began to show. Passes from both teams were going astray and on several occasions a good run ended in no outcome purely because the player ran out of energy.
After the break, it was Japan who demonstrated they were adapting to the hot conditions the best. A well-disciplined high press put pressure on the Black Sticks and they were eventually rewarded with a fourth penalty corner. Oikwawa Shihori was on hand to slam the ball past Rutherford. New Zealand came back hard seeking an equaliser but Japan were able to step up and breakdown the play. A quick break left Vitality Player of the Match Minami Shimizu with a one-on-one with the 'keeper and the nifty midfielder was able to dance around the sliding tackle and slot home to double the Cherry Blossom's lead.
However, New Zealand are not a team to give up and with nine minutes left, New Zealand won a penalty stroke after a foul tackle prevented a certain goal. Anita McLaren made no mistake as she struck the ball into the bottom right-hand corner, and the 2017 Gold Coast gold medallists were back in the game.
With five minutes left Japan were reduced to 10 players and a penalty corner was awarded to New Zealand. The large contingent of Black Sticks fans held their breath but the shot flew harmlessly wide.
"We learnt a lot from our previous game against Australia [Japan lost 3-2]," said Japan's Yui Ishibashi, as she reflected back on her team's performance.
"We planned to operate a high press and then try to work around the New Zealand defence."
Australia (WR:5) and Belgium (WR:13) went head-to-head in the second Pool D match of the day. The first quarter passed without any goals although there is little doubt that the Hockeyroos were the stronger team in the opening salvos.
Their strong build-up play and willingness to run at defenders saw the 2014 World Cup silver medallists rack up a number of shots on goal, although none of them were enough to beat Aisling D'Hooghe in the Belgium goal.
As the second quarter counted down however, the Red Panthers began to find their feet and the play evened out. Stephanie Vanden Borre showed a sublime piece of skill to take the ball out of her own defence and release Anne-Sophie Weyns but the Australia defence looked rock solid as they stuck to the Belgium forwards like glue.
The second half saw Belgium grow in confidence as the Australia threat failed to produce a goal. Where Australia were using their strength and speed to spread the ball around, Belgium were soaking up the pressure and then looking to make quick breaks through the centre of the field. The tactic nearly worked as Alix Gerniers wriggled past two Australia sticks to release Anne-Sophie Weyns. Weyns shot was stopped by Rachael Lynch, who then showed her class to recover and save the rebounded shot.
Still Australia kept knocking on the door, Jodie Kenny lined up for a trademark penalty corner but the Belgium defence held firm. The Red Panthers created their own chances, with Stephane Vanden Borre, Viatlity Player of the Match Barbara Nelen and Michelle Struijk particularly causing problems for the Australia defence.
Lynch was called into action when Louise Versavel had the ball on the edge of the circle. The 'keeper was quickly off her line to close down the danger.
After the game Lynch said: "We knew it would be a hard game and we had to be 'on' every minute of the game. We had some good patches, where we did some really good things and we got lots of opportunities, but then they did too.
"Belgium are a good team and they can be unpredictable but we stuck to our game plan. For the next game our penalty corners need to be better. At this level they are crucial."
Belgium's Stephanie Vanden Borre said: "We had a difficult start and we were finding it difficult to play our game but in the second half we grew into the game.
"Two years ago we really started to increase our physical preparation. We are the best state of fitness we can be. We have just been training, training, training.
"We have a training session called 'turnover Thursday, where we train under duress, this has really helped us to improve our thinking and decision making."
The action resumes on Wednesday 24 July at the Lee Valley Hockey and Tennis Centre when Germany (WR:6) take on Argentina (WR:3) in Pool B at 18:00 (CEST+1) then USA (WR:7) will face England (WR:2) in the second round of Pool C matches at 20:00 (CEST +1).
A full schedule and all the news from the Vitality Hockey Women's World Cup, London 2018 can be found here.