Brown's jumper gave the Falcons (11-11, 6-2 Mid-American Conference) a 70-68 lead with 2:18 left in overtime. Then 52 seconds later, A'uston Calhoun sealed it with a jumper.
Calhoun finished with a double-double of 16 points and 11 rebounds, and Brown scored 12.
Northern Illinois trailed 65-57 with less than 2 minutes to go but closed with a 9-1 run to force overtime. Christian scored seven in the run, including a 3-pointer with 17 seconds left that tied it at 66.
After starting the season just 1-8, the Falcons have won 10 of their last 13 games.