Davis, the regular-season champion, trailed by as many as 11 points in the second half before a 21-6 run gave the Aggies a 67-58 lead with three minutes left.
"We were just a step slow in the first [half]," Davis Coach Jim Les said. "The second half, there was the same physicality, but we responded to it and became the aggressor."
Northridge shot 58% in the first half and led, 36-28, at halftime. But the Matadors unraveled, committing 12 of their 18 turnovers in the second half.
"Our defense got us back into the game," guard Josh Ritchart said. "Once we got some stops, we caught momentum."
Davis shot 67% in the second half.