The Billikens could not take advantage of a Dayton team that was without two of its top forwards and struggled both offensively and defensively in a 63-36 loss to the Flyers.
The game marked the fourth time this SLU has scored less than 40 points.
Junior guard Tommie Liddell III led the Billikens with 10 points, while junior guard Kevin Lisch had nine points and three assists.
Saint Louis, now 11-9 overall and 2-4 in the Atlantic 10 Conference, shot just 37 percent (14 of 38) from the field while Dayton (15-4, 3-3) made 53 percent (24 of 45) of its shot attempts, including eight 3-pointers.
The Billikens host Massachusetts on Saturday at 1 p.m. at Scottrade Center.
Box Score