Jason Lee's GB team need to beat Korea on Saturday to qualify for Sunday's fifth-place play-off match.
DID YOU KNOW?
A unified Great Britain is playing instead of the home nations this year as the Champions Trophy is the last official world ranking tournament before the 2012 Olympics. The Champions Trophy sees eight of the world's best teams invited to face each other and sits behind the Olympics and World Cup in terms of importance
"I thought we played very well for most of the game and didn't deserve to lose," said Lee.
"We controlled the game for long periods but just didn't have the killer instinct to get ahead."
Zwicker put Germany in front against the run of play, before Kirkham marked his 200th appearance with a superb equaliser midway through the first half.
But Britain conceded a penalty in the final seconds, leaving Montag to fire the winner past James Fair to steal victory.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.