After the top 35 skiers had completed the course, Kilde led with a time of 1:31.60 finishing 0.61 seconds ahead of Canada's James Crawford with overall World Cup leader and downhill world champion Marco Odermatt a further two hundredths behind.
Austria's Vincent Kriechmayr, the only man who could stop Kilde from winning the season downhill title, was fourth 0.70 seconds behind the Norwegian.
That left Kilde with an unsurmountable lead in the points table ahead of the final downhill race of the season in Soldeu.
"It's amazing! It's great to fight with the best and so much fun too, it pushes me to do even better next year," Kilde told NBC television.
"I'm always looking for ways to improve, that's what brings me to where I am today," he added.
The victory was the 30-year-old Kilde's 21st World Cup triumph and his sixth in downhill this season and came on the same day that his American girlfriend Mikaela Shiffrin was crowned overall world champion for the fifth time.
"We both support each other every day, that's what pushes us to have the results we have and that makes us proud," he said.
His compatriot Adrian Smiseth Sejersted, who was leading before Friday's race was cancelled due to bad weather, was challenging Kilde but missed a gate and was disqualified.
American Travis Ganong and Italian Matteo Marsaglia both skied their final races before retiring from the sport.
Californian Ganong bows out at the age of 34 after two downhill World Cup wins and six podiums in his career and a downhill silver medal in the World Championships in Beaver Creek in 2015.
Marsaglia, 37, ended his injury-plagued career with one World Cup win in super-G at Beaver Creek in 2012.
