The Lady Blue Jays outshot the Lady Highlanders on goal 20-1 to secure the 5-0 SLIAC shutout in Saturday's regular season finale.
With the victory, Westminster (8-6-2, 5-2-2 St. Louis Intercollegiate Athletic Conference) qualified for the SLIAC tournament for the first time since 2006.
Junior midfielder Monica Bittner scored the first of her two goals on an unassisted strike in the 12th minute. Junior forward Tayisah Pohtos scored unassisted in the 18th minute, while senior midfielder Manyima Njie tallied an unassisted goal in the game's 51st minute.
Bittner closed out the Lady Blue Jays scoring in the 89th minute on an assist by sophomore forward Adrienne Ebersole (Fulton).
Sophomore Ellen Woolsey turned away one shot to blank her sixth opponent of the season.
Westminster - seeded fourth in the SLIAC tournament - plays a semifinal game at No. 1 Webster at 6 p.m. Wednesday. No. 2 Fontbonne hosts No. 3 Principia at 4 p.m. Wednesday in the other semifinal.