Kacsor ran for 244 yards on 40 carries, the fourth time in his career he has rushed for over 200 yards and 12th time in his last 20 games to go over 100 yards. Alex Jeske was 15 of 26 for 206 yards passing.
Duquesne's Dillon Buechel threw 26 yards to Wayne Capers for a 13-3 lead with 7:53 left in the third quarter.
Kacsor, the career rushing leader for Dayton (2-0), then completed drives with third-quarter touchdown runs of 1 and 2 yards and added a 34-yard touchdown with 9:10 left in the game.
Duquesne (2-1), which hadn't trailed this season, took a 6-3 lead in the opening quarter when Sam Martello recovered a Kacsor fumble in the end zone.
Buechel was 20 of 42 with 197 yards, including a touchdown and two interceptions.
AP college football website: www.collegefootball.ap.org