Latvia's Oskars Melbardis took bronze behind the Canadian and German crews who were involved in the first dead-heat in the event since Nagano in 1998.
Ahead of the final run at the Olympic Sliding Centre, the fastest five pilots were separated by less than a quarter of a second in blisteringly quick conditions due to low temperatures.
Kripps, who tops the world bobsleigh driver rankings, had run three good heats, consistently placing first or second, and he needed to pull out another one to secure his first Olympic gold medal.
Four-times world champion Friedrich set the fastest time but Kripps, in the final run of the competition, exactly matched his mark of three minutes 16.86 seconds.
“It’s great. It’s two more people who are as happy as we are," Kripps told reporters. "They’re amazing competitors, we’ve been friends and rivals for years so I couldn’t be happier.”
Germany equalled Switzerland's Olympic record of five golds in the event.
(Reporting by James Pearson, editing by Ed Osmond)
