Weber State (16-9, 11-3) got its biggest lead of the night when Zach Braxton scored two free throws to start the second half ahead 34-29. But North Dakota (17-8, 12-3) answered with a 16-2 run.
In the middle of that streak was a stretch where Weber committed three turnovers in a row, all leading to Hawks' baskets.
"I want to give them a whole lot of credit. That's a good basketball team," Weber State coach Randy Rahe said. "This is one of the best teams they've had in 15 years.
"I also think, too, and I've been seeing it coming for a little while, that we're getting really mentally and physically fatigued," Rahe added. "I especially sensed that in the second half. Our guys worked really hard in the first half and I could see the look on their faces at halftime."
North Dakota was paced by Quinton Hooker's 22 points while Geno Crandall added 19. Cortez Seales scored 17 for the Hawks, who led 56-43 after Seales' 15-foot jumper with 9:15 remaining.
The Wildcats had one more comeback in them, though, and Weber scored 10 straight points to make the score 56-53. Eventually, a pair of free throws by Senglin made the score 63-61 with 4:03 remaining.
That's when Hooker hit a baseline 3-pointer, which was followed by a drive into the lane by Seales for a bucket.
"Our guys had a lot of composure and we've been in this kind of situation a lot over the last two years," North Dakota coach Brian Jones said. "We've got multiple kids that can do that. This place we've never won here. So it's a special day for us."
A last comeback by Weber, down 70-62 with 2:23 left, remained possible until the Wildcats saw four chances at a defensive rebound go awry over a minute-and-a-half stretch.
Wildcats' senior post player Kyndahl Hill, who finished with 14 points and 10 rebounds took note and served notice about it happening again.
"We gave up too many offensive rebounds. You take away those mistakes and we're right there," Hill said. "Those mental mistakes, we're going to fix and be fine."
R North Dakota and Weber State both have three Big Sky losses, but the Hawks have beaten the Wildcats twice this season.
• Up 63-61 with 4:03 left, the Hawks scored nine of the game's next 10 points to go up 72-62.