The South African completed the course in tricky conditions in 4:40 to beat Australia’s Jack Moir by almost three seconds, with the United States’ Aaron Gwin completing the podium a further second adrift.
The problematic forest section caught many riders out but, having pulled a tear-off from his goggles, the three-time world champion was able to cleanly navigate his way through.
“I made a bit of a mistake, I jumped in. I took a bit of a risky line jumping in,” said the Santa Cruz Syndicate rider.
“I kind of bumped off a rut and almost went off course, so I tried to calm it down and ride it smooth to the end. It was a hard race, the rain made it a bit tough.”
The 35-year-old leads the World Cup standings with 292 points. He is two points ahead of Marcelo Gutierrez, with Moir a further 21 back.