Friedrich, who also became a double Olympic champion at PyeongChang 2018, had already won the two-man world title with Thorsten Margis earlier this month and he followed that up by driving Germany's four-man crew to glory.
Alongside Candy Bauer, Martin Grothkopp and Margis, the 28-year-old's sled came home in 3:21.33, pipping Oskars Kibermanis' Latvia (3:21.62) to the post by 0.29 seconds.
Unerring Friedrich clinches 11th world title
The Latvians had led following Friday's first two runs before Germany roared back, with Friedrich recording the eighth World Championship gold medal of his career to date.
And, on home ice, Canada – driven by Justin Kripps – completed the podium in 3:21.78.
Friedrich on top at halfway mark of four-man World Championships
Friedrich makes it six in a row in Altenberg