Brown's 3 with 1:52 left made it 88-85. He hit two free throws with 12 seconds left to ice it. Brown finished with 19. Mike Hughes paced the Eagles (5-9, 1-3 Sun Belt) with 22 points, while Jake Allsmiller and Ike Smith had 16 points apiece.
Wesley Person led Troy (5-10, 0-4 Sun Belt) with 19 points, and Jordon Varnado had 18.
Georgia Southern led 51-36 at intermission, and held a nine-point advantage with 4:26 to go. Troy used a seven-point run - including Vardano's 3-pointer- to draw to within one with 3:11 to go.
Hughes made 1 of 2 from the line to make it 81-79, and then Person's jumper with 24 seconds left tied it. Brown missed a 3-pointer with three seconds remaining and the game went to overtime.
Both teams shot 53 percent or better.