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Video highlights - Germany 5-1 Great Britain
Great Britain's women started their hockey campaign with a 5-1 defeat by Olympic champions Germany.
Great Britain started brightly in the Pool B encounter but the Germans struck first through Fanny Rinne.
Britain were soon level as Crista Cullen scored from a penalty corner but Germany hit back immediately, Eileen Hoffman slotting home a pass.
Hoffman and Rinne both completed doubles after the break with Marion Rodewald adding their fifth goal.
With Argentina, ranked second in the world, being held to a surprise 2-2 draw by the United States in Pool B, a result against the defending champions would have been an important step towards qualification for the semi-finals.
It was disappointing because we unpicked them at times
In the other game in Group B Japan beat New Zealand 2-1.
Great Britain defeated Germany 4-1 in a warm-up match in Dublin last month but have now failed to beat them in a major tournament since the 1996 Olympics in Atlanta.
Head coach Danny Kerry said: "Credit to Germany, they were very clinical and took their chances very well but the scale of the defeat hurts a great deal.
"I think the players know we were off our game in a few areas and we will look hard at that."
Captain Kate Walsh blamed missed chances, particularly when they were only 2-1 down.
"It was disappointing because we unpicked them at times and it was just scoring those chances when we had them," she said.
Bowdon Hightown's Jo Ellis had two early chances as GB enjoyed the better of the opening exchanges and when Anne Panter's shot was deflected wide after 13 minutes Germany had yet to threaten.
However, after their slow start they came to life and took a 25th-minute lead when Rinne's drag-flick was too powerful for GB keeper Beth Storry.
Britain levelled matters with just over five minutes to go to the break when Cullen recovered superbly after a penalty corner routine had broken down and manoeuvred a flick past the German keeper's dive into the left-hand corner.
But within three minutes the Germans restored their advantage, with Hoffman on hand to divert a driven free hit past Storry.
Britain did their best to hit back before the break, with Charlotte Craddock brought down as she ran at the defence at pace to earn a penalty corner.
The German keeper saved well from Cullen's initial shot and when the ball was returned into the centre Cullen slipped and was unable to get her shot on target.
The Germans went 3-1 up 15 minutes into the second half with a slickly-worked penalty corner.
The ball was transferred from the top of the circle to Hoffman, who was lurking outside the right-hand post, to out-flank the British defence and she made no mistake.
Germany ensured they would win when Rinne took a fine pass at the top of the circle, cut across Storry to open up the angle and slotted the ball home.
The British women could have halved the deficit but Panter failed to get a good enough connection after a penalty corner was saved and Germany had the final word.
Storry produced a fine save from a reverse-stick drive from Katharina Scholz but Rodewald was on hand to knock home a reverse-stick effort as the champions made their class count.