The Blue Jays' lone score came on own goal as they suffered their third straight loss in Tuesday's 2-1 setback to the Storm.
After Westminster College (2-6) scored in the 64th minute off a throw-in, Simpson College (8-3) tied the match 2 minutes later when Anthony Ashbridge scored off an assist from Cody Jacobson.
Collin Hemann then delivered the decisive goal for the Storm in the 69th minute when he scored on Spencer Cook's assist.
The Blue Jays were outshot 18-15, and Simpson recorded five corner kicks to Westminster's one.
Westminster returns home for its St. Louis Intercollegiate Athletic Conference opener against Blackburn (Illinois) College at 7 p.m. Saturday.