Austria's Jonas Mueller took silver over half a second behind, ahead of Italian Dominik Fischnaller, who also won bronze four years ago.
Langenhan had laid down his challenge on Saturday when he twice set the track record, including with the first run of the competition, with Mueller the only other athlete to break 53 seconds.
Langenhan was first out of the gate again in the third run on Sunday and was even better with a massive third track record of 52.705.
Former world champion Mueller was also impressive with another sub-53 time and a start record in his third run, but he still lost ground, leaving Langenhan with a relatively comfortable cushion of almost three tenths of a second going into the final run when he was the last man out.
He did not sit back, though, instead roaring to an incredible fourth record in a row of 52.660 seconds for a huge victory.
Having won the World Championship in the last two years, Langenhan has again timed his season brilliantly to peak when it matters most. He is currently third in the World Cup rankings, without winning any of the seven races, but consistently on the podium.