The build up to the Austrian event was overshadowed by the shock retirement of three-time Olympic champion Michael Greis who quit after a poor showing at the season curtain-raiser in Sweden.
However Birnbacher wasn't in the mood to get sentimental about the departure of his countryman Greis and promptly raced to victory in a time of 25.31.01 minutes.
Frenchman Fourcade took the Crystal Globe last year and had hit the ground running with two victories at the season-opening World Cup round in Sweden.
However he was forced to settle for second in Hochfilzen by just 0.4 of a second – some gusting winds in the later stages perhaps to blame for his narrow defeat.
Slovenia's Jakov Fak was third, less than 15 seconds behind the winner in what was a thrilling encounter in Austria ahead of tomorrow's 12.5km pursuit.