Southern Utah (9-18, 6-10 Big Sky) built an 18-8 lead over the first 12 1/2 minutes of the game, including a 3-pointer by John Marshall, as North Dakota missed 16 of its first 19 shots in the contest.
North Dakota trimmed the deficit to four, 57-53, on Lenny Antwi's 3-pointer with 6:03 to go. But a few moments later, Southern Utah made a 9-0 run - including A.J. Hess' 3-pointer - to push the lead back to 13 with just over two minutes remaining.
Southern Utah shot 50 percent on 48 attempts and was 6 of 14 beyond the arc. Despite the win, the Thunderbirds were outrebounded 35-25.
Quinton Hooker led North Dakota (8-20, 4-13) with 24 points on 10-of-15 shooting.