For the 20-year-old Australian Institute of Sport / NSW Institute of Sport skier, the win gave him back-to-back victories in the championships, finishing today's final ahead of two Japanese skiers, Kenji Kono and Hiroomi Takizawa, with World Cup winner Kneller in fourth place.
Despite Kneller, who is Australia's number one ranked ski cross athlete, clocking the fastest time in qualifying and comfortably winning each race on his way to the final, Grimus bolted to the lead as soon as all four athletes left the start gate.
The Mt Buller-based athlete then held the lead all the way to the finish line in a performance that underlined Grimus as the athlete to beat when the series concludes at Cardrona, New Zealand's south island, on August 26.
Grimus also defeated Kneller, the winner of a World Cup event in Italy last December, by a slender margin in yesterday's final to cap off the best consecutive events of his short career.
Grimus said that Kneller, his fellow AIS / NSWIS squad member, has been a source of learning during the last 12 months that they have trained together.
"Scott has a good reputation from at the Olympics and also from winning a World Cup event so to beat him is a great result," Grimus said.
"Scott is very tough to beat and there is no doubt about it, I have learned a lot from him during the last 12 months.
"How he goes over the features and keeps his body position is pretty impressive and I have sort of tried to mimic that and learn as much as possible from him."
Katya Crema, another AIS/NSW squad member, finished in second place in the women's final behind Swiss ace and world number four, Fanny Smith.
Crema scored an emphatic win over Smith in yesterday's final but today the Australian was unable to repeat the victory, finishing ahead of Japan's World Cup skier Chiyako Hioki.
Crema, who trains at Perisher, was second fastest in qualifying behind Smith and leaves Mt Hotham after the two days of competition knowing that she is capable of competing with the world's top echelon of ski cross athletes.