Tevin Svihovec added 14 points for the Bears (18-12), while Tate Unruh netted 12 points on 4-of-7 shooting from the floor. Tim Huskisson pulled down a team-high seven boards for Northern Colorado, which will play Weber State in the semifinals on Friday.
Aaseem Dixon paced NAU (15-17) as he knocked down 6-of-10 attempts from 3- point range en route to a game-high 20 points. Max Jacobsen contributed 18 points and Kris Yanku had 12 points.
Svihovec scored all of his points in the first half as Northern Colorado shot 51.7 percent from the floor en route to a 39-25 lead at the intermission. The Lumberjacks were limited to 39.1 percent efficiency from the field in the opening period.
The Bears extended their advantage to 20 as Dominique Lee scored an easy bucket to give them a 56-36 lead at the 9:15 mark of the second stanza. NAU responded with a 22-4 run that cut the deficit to just two points. Trailing, 62-60, the Lumberjacks came up with a crucial stop as Yanku pulled down a board off a Barden missed layup.
However, Quinton Upshur missed a game-tying layup just before the buzzer, allowing Northern Colorado to escape with the win.
Despite the loss, NAU enjoyed a 32-27 edge in the rebounding battle and knocked down 5-of-11 attempts from behind the 3-point line in the second half.