Peters, who scored in double digits in all 11 of the Crusaders' games this season, had 16 in the first half to help them build a 39-23 lead. Valparaiso (9-2) shot 14 of 27 from distance.
Chicago State (3-7) got as close as 48-36 in the second half. The Crusaders later scored 10 straight on the way to their largest lead at 71-46 with 3:49 left.
Kieran Woods had 14 points to lead the Cougars, who lost their sixth in a row.
Valparaiso holds a 29-3 edge in the all-time series.