Weber State (22-5, 16-2 Big Sky) led 37-29 at halftime but the Lumberjacks used a 20-5 run to begin the second half capped off by a Gabe Rogers 3-pointer to give Northern Arizona a 49-42 lead with 8:32 remaining in the game.
Trailing 69-67 with 11 seconds left, Berry hit a pair of free throws to send it to overtime and the Wildcats scored the first seven points in overtime to hold off Northern Arizona (11-18, 8-10).
Rogers finished with 25 points while hitting six 3-pointers to lead the Lumberjacks. DeWayne Russell had 17 points, seven assists and six rebounds. Max Jacobsen finished with 17 points.
Weber State shot 47.3 percent from the field and was 19 of 23 from the free-throw line.