The 31-year-old shot clean en route to maintaining his unbeaten record this year, finishing 3.1s ahead of compatriot Quentin Fillon Maillet.
Home favourite Benedikt Doll completed the podium with bronze.
Despite flawless shooting it was Fourcade's skiing that proved the difference with the five-time Olympic champion extending a 1.3s lead in the final 1,400m.
"It's quite unbelievable," he said. "It's not only about skiing - it's also about being accurate and fast in the shooting and I'm satisfied with the win.
"You know - especially with Quentin - he will never stop pushing and it was really hard at the end because I knew I had to give more than my best to beat him."
Victory strengthens Fourcade's position at the top of both the World Cup sprint and overall standings ahead of the next event in Pokljuka, Slovenia.