Kwamain Mitchell netted 18 points as the Billikens (23-5, 12-2 A-10) reeled off their 11th consecutive victory.
The win enabled Saint Louis to stay one game ahead of Virginia Commonwealth in the battle for the top spot of the Atlantic 10 Conference.
The Colonials (12-15, 6-8) got a combined 26 points from Kevin Larsen and Lasan Kromah in the loss.
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