Curry's dagger with 6:22 remaining put the Dukes up 67-57 with 6:28 left to play, and was one of four 3-pointers he buried in the game. Curry scored more than 20 points for the seventh time this season.
James Madison (13-5, 3-2 Colonial Athletic) shot 10-for-19 from 3-point range, with Shakir Brown and Jackson Kent each hitting two. The Dukes shot 67-percent from the floor in the first half, leading 42-27 at the break.
Northeastern (11-7, 3-2) steadily cut the gap after halftime, coming as close as 61-55 before Kent and Curry hit consecutive treys.
Yohanny Dalembert scored 14 for James Madison.