DePaul senior Sammy Mejia scored eight-straight points in a late 14-0 run by the Blue Demons and the Jayhawks never regained the lead. Mejia knocked down three-pointers on consecutive possessions late in the second half, tying the score and subsequently giving the Blue Demons a three-point lead that they would not relinquish.
In addition to Chalmers' 15 points, two other KU players reached double figures. Sophomore Julian Wright scored 12 points for the Jayhawks, and freshman forward Darrell Arthur added 10 points and five rebounds.
Mejia paced DePaul with 23 points and eight rebounds while Wilson Chandler netted 12 and pulled down seven boards.
After a slow start by each team, KU used a 9-0 run and held the Blue Demons scoreless for the final 7:12 of the first half to take a 26-17 lead into the break. The Jayhawks got balanced scoring in the first half, led by six points apiece from Chalmers and Arthur. Kansas shot 50 percent in the opening stanza, while holding DePaul to just 6-of-27 from the field and forcing them into 11 turnovers.
KU continued its hot shooting early in the second frame, as a Wright dunk stretched the KU lead to 37-23 with just over 14 minutes to play. However, DePaul answered with an 8-0 run to get back into the game.
The Jayhawks held the Blue Demons to 40.4 percent shooting for the game and forced 17 turnovers, but were outrebounded by DePaul, 35-30, and committed 15 turnovers of their own.
KU will next be in action on Dec. 4 when USC visits Allen Fieldhouse. Tip is set for 8 p.m., and the game will be televised nationally on ESPN2.