Riding her Olympic horse, Don Auriello, Vilhelmson-Silfven shrugged off the pressure of performing at her home event to set a stunning personal best score of 84.7 per cent.
Her previous personal record in freestyle was 79.37 per cent, set last year at the Stockholm World Cup Grand Prix.
Victory handed Vilhelmson-Silfven another 20 points to take her onto 46, which should be sufficient for her to qualify for April's finals in Gothenburg.
Kristina Sprehe came second on the night with Desperados FRH to continue her consistent form. The German scored 82.77 per cent, off the back of 82.27 per cent in her last outing in Stuttgart in November.
Another Swede, Patrick Kittel, finished third with 82.71 on Watermill Scandic-HBC.
Sprehe wins 17 points (51 overall), with Kittel claiming 15 (30 overall).
The action moves to London on December 17 and 18, with the Olympic champions back in the saddle.