The Wildcats (14-5, 9-2 Big Sky), who opened conference play 9-0 before being swept last week at Montana State and league-leading Montana, got back on the winning track by shooting 46 percent and outrebounding North Dakota 40-28.
Josh Schuler had 12 points for the Fighting Sioux (8-12, 5-6), who had won four of their past five games.
Weber State opened the second half with an 11-0 run to take a 40-26 lead. North Dakota got within 53-48 with 6:44 remaining before Berry hit a 3-pointer that sparked a game-ending 13-3 run for the Wildcats. Berry had seven points in the spurt, and Otis had four.
Weber State hit 4 of 5 3-pointers in the second half after missing all five attempts before the intermission.
Maryland point guard Melo Trimble, considered a lock to leave the program before struggling in the second half last season, has withdrawn from the NBA draft and will return for his junior season.
Louisville's Chinanu Onuaku, who recently underwent a medical procedure to correct a heart rhythm issue detected during the combine, will keep his name in the NBA draft pool.
Andrew White III will return to the Nebraska men's basketball team next season after removing his name from the NBA draft.