Lochner and Georg Fleischhauer dominated the event from start to finish to end an incredible 1.34 seconds clear of Friedrich, who had been seeking a record fifth gold, and his brakeman, Alexander Schuller.
Adam Ammour and Alexander Schaller took bronze.
Beijing was the first time a country had swept the medals in any bobsleigh event, and now Germany have done it again in the same event.
Having been the bridesmaid for so long, Lochner has been on top in the World Cup all season, winning six of the seven Two-Man races as Tuesday’s medallists underlined their total dominance by filling all three podium places in six of the seven races.
He carried that form into the Olympics, taking a grip on the event on Monday as he opened a huge 0.8-second lead over Friedrich.
On Tuesday, the coldest night of the Games so far in Cortina, the ice presented a real challenge in the upper parts of the course, and Lochner’s first-out time of 54.89 initially looked to have been sub-par.
However, the opposite was true as Friedrich had to fight some early skids and clocked 55.01 to send Lochner into the final run with a hefty cushion.
He duly signed off with the fastest time of the fourth run to end up a huge 1.34 clear in an event that is often decided by hundredths.
Friedrich came into the Games level with fellow pilot Andre Lange and brakeman Kevin Kuske on four golds, but after adding a silver, he still trails Kuske in the all-time bobsleigh rankings due to the latter's two silvers.
He will get a chance to climb above him when all three German pilots go again in the four-man, for which training starts on Wednesday morning.
Americans Frankie Del Duca and Josh Williamson finished fourth, with Romanian duo Mihai Cristian Tentea and George Iordache producing a fabulous series of runs to take a surprise fifth place.
Germany won all three team bobsleigh golds in Beijing, missing out only on the monobob, which again went to the United States this week.
They will start as favourites to complete another team sweep via the four-man and two-woman events over the remaining days, which will come as a timely boost after disappointments around the rest of the Games have seen them struggling to match their usual huge medal haul.