Pendarvis Williams led Norfolk State (1-11) with 16 points. Kyle O'Quinn added 15 points and nine rebounds before fouling out with 7:37 left.
The Dukes, who got a season-high 51 points from the bench, outscored the Spartans 34-14 off turnovers and 36-13 from the foul line. DU, which entered the game with a 62.2 free throw shooting percentage, hit 36-of-45 (80%) from the stripe.
"Defensively we rebounded the ball and helped each other," said head coach Ron Everhart. "Offensively we're moving the basketball better and our playmakers are making plays. I thought T.J. McConnell and Mike Talley did a good job of running our basketball team. We are a much better basketball team than we were a month ago."
The Dukes increased the lead to 51-30 on a Monteiro layup at the 16:08 mark of the second half. Norfolk State, which was playing the last of six consecutive road games, would get no closer than 20 the rest of the way.
The Duquesne lead reached 30 on a Monteiro layup with 7:58 left. DU led 86-56 with 2:54 remaining before the Spartans closed the game with a 17-9 run for the final margin.
Johnson went 9-of-9 from the line in eclipsing his previous career high of 17 last reached in the season-opening win over Bluefield State.
"To be honest, I've been waiting for him to have this kind of game," said Everhart of the sophomore guard. "Sean is a tough kid. He listens and works hard in practice every day. He's always giving you everything he's got."
"I didn't realize I'd scored that many points," said Johnson. "I just wanted to play hard and get the win."
DU shot 47.4 percent from the field and forced 26 Norfolk State turnovers. The Dukes, who held Norfolk State to 38.6 percent shooting, outrebounded the Spartans 42-34.
Duquesne returns to action at Saint Joseph's (5-8) on Wednesday, Jan. 5 at 7:00 p.m. in the Atlantic 10 opener for both schools.
- Duquesne, which has scored at least 79 points in its six Palumbo Center games, is averaging 92.8 ppg. at its on-campus home where it is now 5-1 ... the win was DU's sixth by 20 or more points this season.
- The Dukes have had at least five double-digit scorers in six of their seven wins (the lone exception was the 81-54 win over IUPUI where DU had four in double digits and one with nine).
- Duquesne is now 6-0 when Sean Johnson scores in double figures.
- Duquesne, which played Northwestern State and Norfolk State in a span of 48 hours, forced 54 turnovers in the two games ... DU outscored the two by a combined 73-to-22 off turnovers.
- The Dukes have one non-conference game remaining on the regular season schedule at Houston Baptist on Jan. 8.