Lamar moved to 16-8 overall, 7-3 in the conference by avenging a 74-62 loss two weeks ago at NSU. The Demons dipped to 14-10 overall and 7-3 in the league.
NSU got 16 points, 13 rebounds and four blocked shots from senior center William Mosley, with James Hulbin and Tyler Washington adding 11 points. The Demons shot 42 percent from the floor, including 8-of-14 on 3-pointers, but the Cardinals sank 49 percent overall while outscoring the visitors 46-20 in the paint and 20-4 off turnovers.
"Getting outscored 26 inside, and the points off turnover stat, those are pretty telling," said 13th-year Demons coach Mike McConathy. "They were attacking us, and we were not attacking them. It's pretty frustrating we didn't compete any better. They just kicked our tails. They did a tremendous job, and it's unfortunate we didn't compete any better, but we'll hopefully learn a hard lesson from this."
Lamar rang up 11 unanswered points midway through the first half to wipe out a 24-19 NSU lead. Point guard Shamir Davis, the Demons' leading scorer all season, exited the game five minutes into action after getting hit with his second foul, and Northwestern struggled offensively against a rugged man-to-man Cardinals defense.
The margin stretched to 40-30 at halftime as the 11 straight points launched a closing 21-6 run over the last nine minutes. NSU got no closer than nine points in the second half.
"Shamir getting into foul trouble hurt. We didn't do a very good job without him, we didn't force any action, and they pretty much manhandled us and were very physical," said McConathy. "We turned the ball over 18 times and that's twice as many as we had in Saturday's game."
Davis managed only five points, nine under his average.
"Give Lamar a lot of credit for protecting the basketball and doing good, aggressive things with it," he said. "Seven turnovers against a team that averages nine steals a game, that's really fine basketball. We didn't get the easy baskets and other than William Mosley, just were not very good inside offensively or defensively."
Mosley passed another milestone, edging past Louisiana Tech great Randy White by one to take over ninth on the Southland's career rebounding rankings with 1,049. He moved within three blocks of 11th on the NCAA all-time list and is now seven shy of 10th.
Lamar got 16 points and 11 rebounds by Devon Lamb, 12 from Anthony Miles who went 10-of-14 from the line, and 11 by Brandon Davis. The Cardinals made more free throws, 16, than the Demons attempted (14).
NSU stays on the road to play Saturday evening at Southeastern Louisiana, then lines up at home Monday night at 7 against McNeese in its third game in six days.