'Cold and shaking' Charlie Hatton wins mountain bike world gold in Fort William
As rain fell in the Scottish Highlands, Hatton mastered the mud to post a time of four minutes 26.747 seconds.
He set a pulsating time, finishing 0.6sec ahead of Austria's Andreas Kolb with another Briton Laurie Greenland finishing third.
Defending champion Loic Bruni came in fourth and world number one Loris Vergier could only manage sixth.
"I'm gobsmacked," the world number 17 said. "I'm not sure if I'm shaking because I'm cold or I'm nervous or all of the above."
The English rider has never won a World Cup race but can now don the rainbow jersey as world champion.
"That was absolutely insane," Hatton said. "I knew I was riding well this weekend. But I never ever expected the win."
Austria's Valentina Holl won her second consecutive women's mountain bike downhill title ending two seconds faster than any other rider.
Five-time world champion Rachel Atherton, who dislocated her shoulder on Thursday, came in eighth.
The winding downhill track is made up largely of rocks and dirt with jumps and bumps marked out by tape on a barren mountainside at Fort William.
The mentally and technically challenging course of 2.8km drops 550m with a lively crowd welcoming each rider at the finish.