High-flying 5-foot-10 senior guard Brison White provided two of the noteworthy slams and picked off a career-best five steals, half of the haul by the Demons (11-11, 7-4 Southland).
White scored 11 points, including a tomahawk jam off one of Jalan West's nine assists following a first-half Patrick Robinson swipe, and the other a reverse dunk after his last steal with 1:37 remaining.
Freshman guard Zeek Woodley, scoring all of his 13 points while propelling Northwestern to a 45-32 halftime advantage, made the third super stuff when he soared to make a one-handed catch of a lob from West.
Woodley rocked it through early in a commanding 21-4 run away from a 17-all tie. White's tomahawk dunk also came in that stretch.
Nicholls senior Dantrell Thomas, playing 30 miles from his hometown of Many, matched his career best with 28 points as he drained 14 of 16 free throws.
He also snagged 10 rebounds, but the Colonels (10-10, 7-4) had only one other double-digit scorer---T.J. Carpenter with 10.
The outcome pushed Northwestern into a tie for third in the loss column in the 14-team league standings.
The Demons visit second-place Sam Houston State (17-6, 9-2) tonight and don't play at home again until March 6.
After falling behind by as many as 17 in the first half, Nicholls twice clawed back within three points.
Northwestern ran off eight straight points midway through the second half to regain control, 71-59, and posted five unanswered, three by White after a rugged Robinson basket inside ended a 10-0 burst by the visitors to within 74-71 with 3:34 remaining.
The Colonels sank just 40 percent overall and 26 percent of their 3-pointers as the Demons continued to display newfound defensive acumen which has combined with good rebounding and hot 3-point shooting as key factors in their winning streak.
Northwestern held the opponent to 40 percent aim or worse for the fourth time in the six wins, won the rebounding battle (41-38) for the fourth straight game, and its 41 percent 3-point aim was the fifth over 40 percent in the streak as the Demons have canned 47 percent overall.
DeQuan Hicks and West each barely missed double-double performances. Hicks topped the Demons with 17 points and nine rebounds.
West scored 12 and enhanced his No. 11 NCAA ranking in assists (6.4 average) with his fourth consecutive game of eight or more dimes.
The Demons got seven rebounds apiece from Marvin Frazier and Ryan King.
With scoring from 10 players, Northwestern out-produced Nicholls 38-20 in points in the paint.
"Nicholls is very well coached, very good at what they do, and we were able to hold them to 40 percent shooting and 26 percent on 3-pointers," said Demons' coach Mike McConathy. "We got contributions throughout the roster, including (by) Patrick Robinson, who rarely stats out on the box score but time and again makes winning plays for us.
"We had a lot of bright spots all the way around," said McConathy. "Zeek with 13 first-half points got us going. Marvin Frazier and Ryan King gave us really good production (combining for 15 points and 14 rebounds). Ryan (a career-high 7 points) was phenomenal. He's come a long way in the last few weeks so with him and a healthy Marvin, our back line is much better than it was a few weeks ago."
The Demons wrapped up a four-game homestand while extending their win streak to the third-longest run in McConathy's 15 seasons.
Last year's 23-9 NCAA Tournament team posted nine wins in a row, the best by the Demons in 37 seasons.
The 2007 Demons had six straight victories, and the 2006 NCAA Tournament squad twice notched eight consecutive.