The Dukes scored 31 points off 21 turnovers and shot 50 percent from the field (28 of 50).
Duquesne led 44-23 at halftime, after holding the Ragin' Cajuns to just 8-for-36 shooting in the first half (22.2 percent).
Louisiana-Lafayette shot 34.3 percent in the game (24 of 70), and was outscored 32-24 in the paint.
Duquesne led by as many as 24 points, 74-50, on Jones' free throw with 5:36 to play.
Kadeem Coleby led the Ragin' Cajuns (3-4) with 11 points and 11 rebounds.
The Ragin' Cajuns never led and tied it at 2-2, before Duquesne went on a 15- 2 run.